Genetic characteristics of mumps virus isolated from one outbreak in Henan province in 2016

Abstract

Objective To analyze the genetic characteristics of mumps virus (MuV) isolated from an outbreak in Henan province in 2016 and to provide reference data for the control of mumps in Henan province. Methods Swab specimens were collected from a mumps outbreak in Henan province in 2016. One virus strain was selected for whole genome sequencing after virus isolation and genotyping. MEGA7.0 software was used to construct phylogenetic tree, to calculate P-distance and to analyze the characteristics of genes encoding small hydrophobic protein (SH), fusion protein (F) and hemagglutinin neuraminidase (HN). Results Five swab specimens were collected in the outbreak and five MuV strains were successfully obtained. Phylogenetic analysis showed that all of them belonged to genotype F with a P-distance of 0.047 (0.046-0.049) with the reference strain. The P-distance among the five MuV strains was 0.001 (0-0.003). Results of the whole genome sequencing of one MuV strain showed that the P-distance with the reference virus was 0.053 (0.018-0.072) and the smallest P-distance with genotype F was 0.018. Compared with the vaccine strain (HQ416907.1), the amino acid at 28-30 site of SH protein was IML. The 91, 195 and 383 amino acid sites in F protein were related to the pathogenicity of MuV, but no mutations were found in these sites. Some mutations were found in HN protein, such as P354Q, E356D and K464N, which were associated with the immunological characteristics of MuV. Conclusions MuV strains isolated from the outbreak in Henan province in 2016 belonged to genotype F. The genetic characteristics of these MuV strains were similar to those prevalent in other provinces of China. Key words: Mumps virus; Genetic characteristics; Analysis