Table 2 Molecular determinants of virulence, host specificity and drug resistance in Moroccan H9N2 isolates

PB2

147 V, 504 V

318R, 590S, 661 T

PB1

13P

PB1-F2

66 N

82 L

Truncated protein of 52 aa

PA

127 V, L550, 672 L

I100, R312, 409 N

PA-X

Full length 252 amino acids

HA^a

158 N, 183H, 226 L, 391 K

Cleavage site: RSSRGL*F

Glycosylation sites:

29NSTE, 82NPSC, 105NGTC, 141NVTY, 298 NSTM, 305NISK, 492NGTY

NP

372D

NA

None

No stalk deletion

M1

15I

M2

D16

31 N (amantadane resistance)

NS1

42S, 189D

No 80–84 deletion and GSEV PL motif

NS2

31 M, 56H