Effect of the PB2 and M Genes on the Replication of H6 Influenza Virus in Chickens
Table 1
Experimental infection of 7 + 1 reassortant H6 viruses.
Virus
No. of positive trachea/total no. of birds for each bird
Day 3
Day 5
Parental strain
A/teal/Hong Kong/W312/97 (H6N1)
3/3 (3.5, 3.0, 3.7)
3/3 (4.0, 2.5, 3.7)
A/duck/Shantou/5540/01 (H6N2)
0/3 (—, —, —)
0/3 (—, —, —)
Reassortants (W312 backbone)
ST-PB2
0/3 (—, —, —)
0/3 (—, —, —)
ST-PB1
3/3 (3.7, 4.0, 2.7)
3/3 (3.0, 3.5, 3.0)
ST-PA
3/3 (3.5, 3.5, 3.0)
3/3 (3.5, 3.0, 3.5)
ST-HA
0/3 (—, —, —)
2/3 (—, 1.0, 1.5)
ST-NP
3/3 (2.7, 3.0, 2.7)
3/3 (3.0, 4.0, 3.3)
ST-NA
3/3 (3.5, 3.5, 3.5)
3/3 (3.5, 3.5, 3.0)
ST-M
0/3 (—, —, —)
0/3 (—, —, —)
ST-NS
3/3 (3.3, 3.5, 4.0)
3/3 (3.5, 3.5, 3.7)
Chimeric PB2 gene
WST-PB2 AflII
0/3 (—, —, —)
0/3 (—, —, —)
STW-PB2 AflII
3/3 (3.5, 3.0, 3.5)
3/3 (3.5, 3.0, 3.5)
Chimeric M gene
WM1-STM2
0/3 (—, —, —)
1/3 (1.0, —, —)
STM1-WM2
3/3 (2.7, 3.0, 3.7)
3/3 (3.0, 3.0, 3.3)
— Indicates no HA was detected in allantoic fluid from eggs inoculated with original swab sample. Detection limit was 0.5 [. No virus was recovered from cloacal samples on both days.
