Genomic signatures of influenza A pandemic (H1N1) 2009 virus

• Published in: Emerging infectious diseases Vol. 15; no. 12; pp. 1897 - 1903
• Main Authors: Chen, Guang-Wu, Shih, Shin-Ru
• Format: Journal Article
• Language: English
• Published: United States U.S. National Center for Infectious Diseases 01.12.2009; Centers for Disease Control and Prevention
• Subjects: Amino Acid Sequence; Animals; Birds; Causes of; Disease Outbreaks; Entropy; Gene mutations; Genetic aspects; Genome, Viral; Health aspects; Humans; Influenza; Influenza A Virus, H1N1 Subtype - classification; Influenza A Virus, H1N1 Subtype - genetics; Influenza A Virus, H1N1 Subtype - pathogenicity; Influenza viruses; mutation; pandemic (H1N1) 2009 virus; signatures; species specificity; Swine; Swine influenza; Viral Proteins - chemistry; viruses; China
• ISSN: 1080-6040; 1080-6059
• DOI: 10.3201/eid1512.090845

Adaptive mutations that have contributed to the emergence of influenza A pandemic (H1N1) 2009 virus, which can replicate and transmit among humans, remain unknown. We conducted a large-scale scanning of influenza protein sequences and identified amino acid-conserving positions that are specific to host species, called signatures. Of 47 signatures that separate avian viruses from human viruses by their nonglycoproteins, 8 were human-like in the pandemic (H1N1) 2009 virus. Close examination of their amino acid residues in the recent ancestral swine viruses of pandemic (H1N1) 2009 virus showed that 7 had already transitioned to human-like residues and only PA 356 retained an avianlike K; in pandemic (H1N1) 2009 virus, this residue changed into a human-like R. Signatures that separate swine viruses from human viruses were also present. Continuous monitoring of these signatures in nonhuman species will help with influenza surveillance and with evaluation of the likelihood of further adaptation to humans.