Table 1.
Amino acids differing between virus A and B and changes observed between wild-type and resistant viruses.
| Changes between the 2 wild-type viruses | |||
| Gene | Position | Virus A | Virus B |
| PB1 | 537 | S | N |
| 563 | K | R | |
| PA | 14 | V | I |
| 716 | K | Q | |
| HA | 114 | N | D |
| NP | 194 | V | I |
| 270 | V | I | |
| 444 | V | I | |
| Changes between the wild-type and resistant viruses | |||
| Virus A to Ar | NS | L95I | |
| NA | H275Y | ||
| Virus B to Br | HA | A15T, F432L | |
| NA | H275Y | ||
NOTE. Eight amino acid differences were observed between the 2 wild-type viruses, demonstrating that the viruses isolated from the 2 patients were not identical at baseline. The only shared mutation selected for under drug pressure between the resistant viral isolates was the NA H275Y mutation.