Work

Genetic characterization on the nucleoprotein and fusion gene of wild-type measles virus circulating in Shanghai, 2001–2022

Year: 2025

Type: article

Abstract: ABSTRACTMeasles is an acute and highly contagious disease in humans. Thus, continuous virologic surveillance has been conducted since 2001 in Shanghai, enabling a detailed study on the evolution of the nucleoprotein (N gene) and fusion gene (F gene) of the measles virus (MeV) over 21 years. From 2001 to 2022, the Shanghai Center for Disease Control and prevention (SCDC) had isolated 1405 MeV strains. Among MeV strains, 6 strains were D8 genotype, 8 strains were B3, 12 strains were H1b and the rest were H1a. Reverse transcription polymerase chain reaction (RT-PCR) was performed to amplify the 3' end of the N gene (450 nt) and the complete sequence of the F gene (1622 nt) from the viral isolates. After sequencing the positive RT-PCR products, nucleotide and amino acid phylogenetic analyses were performed. The substitution rates were 0.89×10-3 and 2.20×10-3 substitutions site-1year-1 for the F gene and N gene in Shanghai, respectively. The nucleotide and amino acid similarities of the N gene of 13498 MeV isolates worldwide were 89.1%~100.0% and 90.2%~100.0%, respectively, while the nucleotide and amino acid similarities of the F gene of 773 MeV isolates worldwide were 92.4%~100.0% and 94.7%~100.0%, respectively. The F gene had 16 sites with high amino acid mutation, which most of H1a MeV strains varied, compared with the Shanghai-191 vaccine strain. The deletion of the glycosylation site at aa 9-11(NVS) mainly occurred in H1a and H1b of MeV strains. However, the important functional sites in the F gene are conserved. In conclusion, H1a was the dominant sub-genotype of MeVs in Shanghai between 2001 and 2022. There was a significant difference in the similarities of the N gene of H1a, while the F gene of H1a could be divided into two clusters. Cluster 2 was an advantageous branch. The overall genetic diversity of the F gene was more stable than that of the N gene between 2001 and 2022 in Shanghai. In the future, we should still pay more attention on measles surveillance of MeV-F gene or WGS, so as to facilitate the evaluation of measles vaccines, drug development.

Source: Journal of Virus Eradication

DOI: 10.1016/j.jve.2025.100589