Molecular characterization and phylogenetic analys

Authors: Yun Hee Baek Jeung Hyun Park Young Jun Song MinSuk Song Philippe Noriel Q Pascua YoonSoo Hahn HeonSeok Han OkJun Lee KiSoon Kim Chun Kang YoungKi Choi

Publish Date: 2009/02/20

Volume: 47, Issue: 1, Pages: 91-100

PDF Link

Abstract

To investigate the genetic characteristics of human influenza viruses circulating in Chungbuk province we tested 510 clinical samples of nasopharyngeal suction from pediatric patients diagnosed with respiratory illness between June 2007 and June 2008 Genetic characterization of the HA genes of H3N2 isolates indicated the relative higher similarity to A/Virginia/04/07 996 rather than that of A/Wisconsin/67/2005 984 a Northern Hemisphere 2007∼2008 vaccine strain based on amino acid sequences We found several altered amino acids at the H3 HA1 antigenic sites compared with the vaccine strain K140I at site A K158R at site B and K173N H471 or K173Q and S262N at site E but there was no antigenic shift among the H3N2 viruses Interestingly A/Cheongju/H383/08 and A/Cheongju/H407/08 isolates had single amino acid substitution at D151G on the catalytic site of the N2 NA while A/Cheongju/H412/08 and A/Cheongju/ H398/07 isolates had one amino acid deletion at residue 146 Furthermore we found that 25 3 out of 12 isolates of the H3N2 subtype viruses had the amino acid substitution at position 31 on the M2 protein Aspartic acid to Asparagine and confirmed their drugresistance by biological assays Taken together the results of this study demonstrated continuous evolutions of human H3N2 viruses by antigenic drift and also highlighted the need to closely monitor antigenic drug resistance in influenza A viruses to aid in the early detection of potentially pandemic strains as well as underscore the need for new therapeutics

Keywords: