Analysis on genetic characteristics of rubella virus isolates from 2011 to 2017 in Shanghai, China / 中华实验和临床病毒学杂志

ABSTRACT

Objective@#To analyze the molecular epidemiological characteristics of rubella virus wild strains isolated in Shanghai during 2011-2017.@*Methods@#Throat swabs were collected from suspected measles or rubella patients in Shanghai during 2011-2017, which were identified as rubella and excluded measles by laboratory tests. Throat swabs were used to conduct cell culture for rubella virus isolation. After identification by RT-PCR, the nucleic acid of gene E1 of rubella virus was amplified and sequenced, followed by molecular epidemiological analysis.@*Results@#Totally 395 strains of rubella virus were isolated from 684 throat swabs. Compared 377 isolates with the WHO reference strains of all genotypes, phylogenetic tree was constructed based on the amplified 739 nucleotides sequences. These isolates were characterized as two genotypes respectively, 109 strains were defined as genotype 1E which were closer to the WHO reference strain from China (RVi/Shandong.CHN/0.02/), and others were genotype 2B while 5 strains of them were defined as a lineage. Most of the nucleotide mutations were nonsense mutation, and the amino acid sequences were highly conserved. All the genotype 1E rubella viruses except one strain had the same mutation at aa338 site.@*Conclusions@#Two genotypes of rubella virus circulated in Shanghai during 2011-2017.Genotype 1E appeared to be the predominant genotype during 2011-2013, genotype 2B was continuously existing since being found in 2011 and appeared to be the predominant genotype during 2014-2016.