Phylogenetic and Molecular Characteristics of Wild Bird-Origin Avian Influenza Viruses Circulating in Poland in 2018−2022: Reassortment, Multiple Introductions, and Wild Bird–Poultry Epidemiological Links

Table 4

Molecular markers changing AIV biological properties [30–32] detected in HPAIV sequences of the H5 subtype in Poland from 2020 to 2022.

Segment	Mutation	N	Phenotype
PB2	I292V	18	Polymerase activity in mammalian cells [34, 35] ↑, virulence in mice ↑ [34]
PB2	K389R	40	Polymerase activity and replication in mammalian cells ↑ [36]
PB2	K526R	1	Polymerase activity in mammalian cells ↑ [37]
PB2	V598T	41	Polymerase activity and replication in mammalian cells ↑, virulence in mice ↑ [36]
PB2	S715N	42	Virulence in mice ↓ [38]
PB2	L89V + G309D	38	Polymerase activity in mammalian cells ↑, virulence in mice ↑ [39]
PB2	L89V + G309D + T339K + R477G + I495V + K627E + A676T	35	Polymerase activity in mammalian cells ↑, virulence in mice ↑ [39]
PB1	D3V	42	Polymerase activity and viral replication in avian and mammalian cells [40]
PB1	D622G	42	Polymerase activity and virulence in mice ↑ [41]
PB1	S678N	1	Replication in avian and mammalian cells ↑ [42]
PB1-F2	N66S	21	Viral replication, antiviral response, and virulence in mice ↑ [43, 44]
PA	S37A	42	Polymerase activity in mammalian cells ↑ [45]
PA	K158R	2	Polymerase activity in mammalian cells ↑ [40]
PA	P190S	41	Virulence in mice ↓ [46]
PA	N383D	41	Polymerase activity in avian and mammalian cells ↑ [47, 48]
PA	Q400P	12	Virulence in mice ↓ [46]
PA	N409S	42	Polymerase activity in mammalian cells ↑ [45]
HA	S123P	41	Virus binding to α2,6 receptors ↑ [49]
HA	S133A	41	Pseudovirus binding to α2,6 receptors ↑ [50]
HA	S154N	42	Virus binding to α2,6 receptors ↑ [51]
HA	T156A	41	Virus binding to α2,6 receptors ↑, transmission to guinea pig ↑ [51, 52]
HA	V182N	41	Virus binding to α2,6 receptors ↑, Virus binding to α2,3 receptors ↓ [53]
HA	V210I	1	Virus binding to α2,6 receptors ↑ [54]
HA	K394E	42	Fusion pH ↑, HA stability ↓, virulence in mice ↓ [55]
HA	S107R + T108I	41	Fusion pH ↑, Virulence in chickens and mice ↑ [56]
HA	K218Q + S223R	42	Virus binding to α2,3 and α2,6 receptors ↑ [57]
NP	I41V	1	Polymerase activity in mammalian cells ↑ [58]
NP	M105V	30	Virulence in chickens ↑ [59]
NP	A184K	42	Replication in avian cells ↑, virulence in chickens ↑, host immune response ↑ [60]
NP	N319K	2	Polymerase activity and replication in mammalian cells [61, 62] ↑
M1	N30D	42	Virulence in mice ↑ [63]
M1	I43M	42	Virulence in mice, chickens, and ducks ↑ [64]
M1	T215A	42	Virulence in mice ↑ [63]
NS1	P42S	41	Virulence in mice ↑, antiviral immune response in mice ↓ [65]
NS1	I106M	42	Virus replication and virulence in mice ↑ [66]
NS1	C138F	42	Virus replication in mammalian cells ↑, interferon response ↓ [67]
NS1	V149A	42	Virulence in chickens ↑, interferon response in avian cells ↓ [68]
NS1	L103F + I106M	41	Virulence in mice ↓ [69]
NS1	K55E + K66E + C138F	22	Virus replication in mammalian cells ↑, interferon response ↓ [67]
NS1	^227ESEV^230 (PDZ domain)	22	Virus replication in mice ↑ [70], virulence in mice ↑ [70, 71], and virus replication in mammalian and avian cells ↓ [72]

Asterisk () indicates mutations present also in LPAIVs from Poland. N = number of HPAIV sequences having the mutation, ↑ = increased, ↓ = decreased. For mutations identified in HA gene, H5 numbering was used.