Genetic characterization of rubella virus isolated in Guizhou province in 2012 / 重庆医学

ABSTRACT

Objective To identify the rubella virus circulated in Guizhou province in 2012 ,and confirm the genotype and analyze the genetic characterization of rubella virus isolated .Methods The throat swab samples were collected from suspected rubella cases during the rubella outbreak and sporadic in 2012 .Rubella virus isolation was performed using Vero/SLAM cells .The presence of vi-ral RNA was detected using real-time RT-PCR after RNA extraction from infected tissue culture cells .Fragments of 944 nucleotides of E1 genes of the isolates were amplified by RT-PCR ,the PCR products were directly sequenced and analyzed .The phylogenetic trees based on the 739 nucleotide sequences 1E was conducted with the rubella viruses isolated in Guizhou province in 2012 and 32 WHO reference sequences representing 13 genotypes .Results 5 rubella virus strains were isolated in Guizhou province for the first time .The results of phylogenetic analysis showed that all 5 rubella virus isolates belong to genotype 1E .The nucleotide acid and a-mino acid homology among 5 rubella virus isolates were 99 .8% -100 .0% and 100 .0% respectively .Compared with the WHO ref-erence strain (Chinese strain T14-CH-02) ,the nucleotide acid and amino acid homology were 98 .7% -98 .9% and 100 .0% respec-tively ;while compared with another WHO reference strain (Malaysia strains M1-MAL-01) ,the nucleotide acid and amino acid ho-mology were 97 .5% -97 .6% and 99 .5% .Conclusion Genotype 1E rubella virus was the predominant genotype in Guizhou prov-ince in 2012 ,which was similar to the other provinces .This study accumulated the molecular epidemiological baseline date in Guizhou province .