Goñi Natalia, Russi José, Cristina Juan
Laboratorio de Virología Molecular, Centro de Investigaciones Nucleares, Facultad de Ciencias, Iguá 4225, 11400 Montevideo, Uruguay.
Infect Genet Evol. 2009 Mar;9(2):229-34. doi: 10.1016/j.meegid.2008.11.004. Epub 2008 Nov 27.
In order to gain insight into the genetic relations among H3N2 Influenza A virus (IAV) circulating in the South American region from 1999 to 2007, to investigate the presence of adamantane-resistant strains in this region, and to establish the genetic relations among that strains and vaccine strains recommended for the Southern hemisphere, 11 haemagglutinin (HA) H3 IAV sequences obtained from Uruguayan patients were aligned with corresponding sequences from 68 H3 IAV strains isolated in South America and 9 H3 IAV vaccine strains. Maximum likelihood phylogenetic tree analysis was performed using the GTR evolutionary model. The results of these studies indicate that multiple clades co-circulate during most influenza seasons in South America. Strikingly, one strain isolated in Uruguay in 2005 and all strains isolated in that country during the 2007 season bear an HA adamantane-resistant polymorphism. No other strain isolated in South America previous to the 2005 season bears that HA characteristic amino acid change. Only vaccine strains recommended for the 2007 season were assigned to the same cluster with all available IAV isolated in South America for that season. Evolution of IAV in this region appears to be shaped by re-introduction of new strains.
为深入了解1999年至2007年在南美地区传播的甲型H3N2流感病毒（IAV）之间的遗传关系，调查该地区是否存在对金刚烷耐药的毒株，并确定这些毒株与推荐给南半球的疫苗毒株之间的遗传关系，将从乌拉圭患者中获得的11个血凝素（HA）H3 IAV序列与从南美分离的68个H3 IAV毒株及9个H3 IAV疫苗毒株的相应序列进行比对。使用GTR进化模型进行最大似然系统发育树分析。这些研究结果表明，在南美大多数流感季节，多个进化枝同时传播。引人注目的是，2005年在乌拉圭分离出的一个毒株以及2007年该国家分离出的所有毒株都具有HA金刚烷耐药多态性。2005年季节之前在南美分离出的其他毒株均未出现该HA特征性氨基酸变化。只有推荐用于2007年季节的疫苗毒株与该季节在南美分离出的所有可用IAV属于同一簇。该地区IAV的进化似乎受到新毒株重新引入的影响。
