molecular evolution of human h1n1 and h3n2 influenza a virus in thailand, 2006–2009分子进化的人类h1n1和h3n2流感病毒在泰国,2006 - 2009.pdfVIP

Molecular Evolution of Human H1N1 and H3N2 Influenza A Virus in Thailand, 2006–2009 1 1 1 1 Kamol Suwannakarn , Thaweesak Chieochansin , Chitima Thongmee , Jarika Makkoch , Kesmanee 1 1 2 1 Praianantathavorn , Apiradee Theamboonlers , Srinand Sreevatsan , Yong Poovorawan * 1 Center of Excellence in Clinical Virology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand, 2 Departments of Veterinary Population Medicine and Veterinary and Biomedical Sciences, University of Minnesota, Saint Paul, Minnesota, United States of America Abstract Background: Annual seasonal influenza outbreaks are associated with high morbidity and mortality. Objective: To index and document evolutionary changes among influenza A H1N1 and H3N2 viruses isolated from Thailand during 2006–2009, using complete genome sequences. Methods: Nasopharyngeal aspirates were collected from patients diagnosed with respiratory illness in Thailand during 2006–2009. All samples were screened for Influenza A virus. A total of 13 H1N1 and 21 H3N2 were confirmed and whole genome sequenced for the evolutionary analysis using standard phylogenetic approaches. Results: Phylogenetic analysis of HA revealed a clear diversification of seasonal from vaccine strain lineages. H3N2 seasonal clusters were closely related to the WHO recommended vaccine strains in each season. Most H1N1 isolates could be differentiated into 3 lineages. The A/Brisbane/59/2007 lineage, a vaccine strain for H1N1 since 2008, is closely related with the H1N1 subtypes circulating in 2009. HA sequences were conserved at the receptor-binding site. A