TABLE 5.
NA sequence variations of the NAI resistance-associated substitutions identified in human and avian influenza viruses of N1 to N9 NA subtypes
| NA residuea | WT amino acid (subtype) | Amino acid substitution | NA subtype | Polymorphism(s) in database (frequency [%])b |
|||
|---|---|---|---|---|---|---|---|
| Avian | No. of sequences | Human | No. of sequences | ||||
| 147 | N/G (N5/N8) | I/V | N1 | G (99.76), R (0.24) | 2,110 | G (99.83), Q (0.11), R (0.06) | 8,065 |
| N4, N5, N8 | G (86.37), N (13.63)c | 3,258 | G (100) | 4 | |||
| N2 | G (98.78), D (0.65), S (0.58) | 2,776 | N (73.57), D (25.83), G (0.57), Y (0.02) | 8,809 | |||
| N3, N6, N7, N9 | G (99.94), R (0.03), T (0.01), Q (0.01) | 6,733 | G (99.12), Q (0.88) | 113 | |||
| 246 | A (N6) | F/V | N1 | S (99.76), N (0.19), G (0.05) | 2,111 | S (99.38), N (0.57), R (0.05) | 8,061 |
| N4, N5, N8 | A (89.1), S (10.81)d, T (0.09) | 3,276 | A (100) | 4 | |||
| N2 | A (99.96), S (0.04) | 2,775 | A (99.95), T (0.03), G (0.01) | 8,808 | |||
| N3, N6, N7, N9 | A (99.91), T (0.03), V (0.01), S (0.01), P (0.01), G (0.01) | 6,719 | A (100) | 125 | |||
| 427 | I (N4) | L | N1 | I (98.72), V (1.23), T (0.05) | 2,108 | I (85.11), V (14.87), M (0.01) | 8,061 |
| N4, N5, N8 | I (99.97), V (0.03) | 3,277 | I (100) | 4 | |||
| N2 | I (99.39), V (0.4), T (0.22) | 2,771 | I (99.93), V (0.05), M (0.01), T (0.01) | 8,805 | |||
| N3, N6, N7, N9 | I (97.4), T (2.51), M (0.07), V (0.01) | 6,692 | I (100) | 113 | |||
| 274 | H | Y | N1 | H (99.95), Y (0.047) | 2,112 | H (94.31), Y (5.672), N (0.012) | 8,056 |
| N4, N5, N8 | H (99.96), R (0.016), Q (0.016) | 6,176 | H (100) | 4 | |||
| N2 | H (100) | 2,775 | H (100) | 8,808 | |||
| N3, N6, N7, N9 | H (99.97), N (0.014), R (0.014) | 6,729 | H (100) | 125 | |||
a
Position numbers of amino acid substitutions are based on N2 numbering.
b
Data were obtained from the Influenza Research Database.
c
N is 100% in the N5 subtype (350/350).
d
S is 99.55% in the N4 subtype (225/226).