Genetic correlation between current circulating H1N1 swine and human influenza viruses.
BACKGROUND
H1N1 is the main subtype influenza A virus circulating in human and swine population, and has long been a threat to economy and public health.


OBJECTIVE
To explore the genetic correlation between current circulating H1N1 swine and human influenza viruses.


METHODS
Three new H1N1 swine influenza viruses (SIVs) were isolated and genomes sequencing were conducted followed by phylogenetic and molecular analysis of all swine and human H1N1 influenza viruses isolated in China in the past five years.


RESULTS
Homology and phylogenetic analysis revealed that the three isolates possessed different characteristics: the genome of A/Swine/Shandong/1112/2008 was closely related to that of classical H1N1 SIV, while A/Swine/Shandong/1123/2008 was a reassortant with NS gene from the human-like H3N2 influenza virus and other genes from the classical H1N1 SIV, and A/Swine/Fujian/0325/2008 fell into a lineage of seasonal human H1N1 influenza viruses. Genetically, 2009 H1N1 influenza A viruses (2009 H1N1) in China were contiguous to the SIV lineages rather than the seasonal H1N1 human influenza virus's lineage. Furthermore, molecular analysis among human and swine influenza viruses provided more detail information for understanding their genetic correlation.


CONCLUSIONS
These results suggested that in China in the past five years, the classical, avian-like and human-like H1N1 SIV existed in swine herds and the reassortment between H1N1 swine and H3N2 human influenza viruses was identified. In addition, the present data showed no evidence to support a strong correlation between the 2009 H1N1 and the swine influenza virus circulating in China.
Lu
Lu
L
Center for Molecular Virology, CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.
Yin
Yanbo
Y
Sun
Zhongsheng
Z
Gao
Lei
L
Gao
George F
GF
Liu
Sidang
S
Sun
Lei
L
Liu
Wenjun
W
D000818:Animals; D002681:China; D016000:Cluster Analysis; D005838:Genotype; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification*; D053122:Influenza A Virus, H3N2 Subtype / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D007251:Influenza, Human / Q000821:virology*; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D009976:Orthomyxoviridae Infections / Q000662:veterinary* / Q000821:virology; D010802:Phylogeny; D012367:RNA, Viral / Q000235:genetics; D016865:Reassortant Viruses / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D013552:Swine; D013553:Swine Diseases / Q000821:virology*
D012367:RNA, Viral