Volume 20, Number 8—August 2014
Dispatch
Infection with Possible Precursor of Avian Influenza A(H7N9) Virus in a Child, China, 2013
Table 2
Analysis on critical mammalian-adapting amino acid substitutions in H7N9 virus strains.*†
Gene |
Site |
SH/JS01 |
SH/1 |
SH/2 |
AH/1 |
Known mutations |
Relationship to mammalian adaption |
HA | 138 | A | S | A | A | S138A | Mammalian host adaption |
186 | G | G | V | V | G186V | Unknown | |
226 | Q | Q | L | L | Q226L | Unknown | |
228 | G | G | G | G | G228S | Unknown | |
NA | 292 | R | K | R | R | R292K | Osteltamivir and zanamivir resistance |
69–73 deletion | No | Yes | Yes | Yes | Not applicable | Deletion of 69–73 Increased virulence in mice | |
PB2 | 63 | I | I | I | I | I63T | Co-mediate with PB1 677M, to reduce pathogenicity of H5N1 viruses |
89 | V | V | V | V | L89V | Enhanced polymerase activity and increased virulence in mice | |
471 | T | T | T | T | T471M | Viral replication, virulence, and pathogenicity | |
591 | Q | Q | Q | Q | Q591K | Adapt in mammals that compensates for the lack of PB2–627K | |
627 | E | K | K | K | E627K | Enhanced polymerase activity and increased virulence in mice | |
701 | D | D | D | D | D701N | Enhanced transmission in guinea pigs | |
PB1 | 99 | H | H | H | H | H99Y | Results in transmissible of H5 virus among ferrets |
353 | K | K | K | K | K353R | Determine viral replication, virulence, and pathogenicity | |
368 | V | I | V | V | I368V | Results in transmissible of H5 virus among ferrets | |
566 | T | T | T | T | T566A | Determine viral replication, virulence, and pathogenicity | |
677 | T | T | T | T | T677M | Co-mediate with PB2 I63T to reduce pathogenicity of H5N1 viruses | |
PA | 100 | V | A | A | A | V100A | Related to human adaption |
356 | R | R | R | R | 356R | Related to human adaption | |
409 | S | N | N | N | S409N | Enhances transmission in mammals | |
M1 | 30 | D | D | D | D | N30D | Increased virulence in mice |
215 | A | A | A | A | T215A | Increased virulence in mice | |
M2 | 31 | N | N | N | N | S31N | Reduced susceptibility to amantadine and rimantadine |
NS1 | 42 | S | S | S | S | P42S | Increased virulence in mice |
*HA, hemagglutinin; NA, neuraminidase; SH/JS01, A/Shanghai/JS01/2013(H7N9); SH/1, A/Shanghai/1/2013 (H7N9); SH/2, A/Shanghai/2/2013 (H7N9); AH/1, A/Anhui/1/2013 (H7N9); PB, RNA polymerase basic subunit; PA, RNA polymerase acidic subunit; M, matrix gene; NS, nonstructural gene.
†Boldface text indicates the mutant amino acids sites related to mammalian host adaption and increased virulence.
1These authors contributed equally to this work.
2These authors contributed equally to this work and share senior authorship.