Sequencing of measles virus vaccine strain Shanghai-191 genome and comparative analysis of nudeotide sequences between vaccine strain and wild-type strains in China / 中华微生物学和免疫学杂志

ABSTRACT

Objective To explore the distinction between measles vaccine strain Shanghai-191 (S- 191) and wild-type strains in China at molecular level. Methods After having been amplified by RT-PCR, the nucleotides of S-191 was sequenced and analyzed with reference to the sequences obtained from Gen- Bank, which includes 24 whole genome sequences, 211 sequences of wild-type strains isolated from China and WHO reference strains. Results The sequence of S-191 strain had been submitted to GenBank. Phylo- genetic analysis of the COOH terminal 456 nucleotides coding for the nucleoprotein (N) indicated that most of the measles virus strains from China were members of clade H1. The genetic distances between the virus strains detected in a number of provinces and S-191 strain were 6.7% -8.2%. It is noteworthy that the muta- tion rate of non-coding regions was considerably higher than that of coding regions. The mutation rate of N gene was the highest among all of the coding regions. Conclusion This report shows that genotype H1 is widely distributed throughout the country. The circulation has no apparent geographic and temporal restric- tion. The evolution of measles virus should be closely followed.