Abstract:

Objective To investigate the virome characteristics of the mosquitoes carrying Japanese encephalitis virus (JEV) for evidence in estimating the public health risks arising from mosquito-borne viruses. Methods According to the National Surveillance Program for Vector Pathogens (Trial), the infected mosquito samples carrying JEV were collected in the National Surveillance System for Mosquito-borne Pathogens from June to September 2022, and the data were further verified. Then the JEV positive mosquito samples with high nucleic acid quality from different provinces and distinct mosquito species were selected to undergo virome sequencing and bioinformatics analysis. The viral sequences were aligned and assembled, and phylogenetic analysis was performed in the important arboviruses that were annotated. Results In this study, a total of 8 pools with JEV-positive mosquitoes were investigated from 6 provinces, including Guizhou, Hubei, Jiangsu, Chongqing, Gansu and Yunnan. The mosquito species consisted of Anopheles sinensis, Culex quinquefasciatus and Culex tritaeniorhynchus. The results of virome sequencing showed that a total of 41 virus families and 118 known viruses were annotated. Among them, the abundance of Rhabdoviridae was relatively higher in more than half of the sampling sites. Twenty-two virus families were annotated in all 3 mosquito species. Quang Binh virus (QBV) was annotated in the mosquitoes sampled from 6 pools, and six near-full-length QBV sequences were obtained by assembly. Banna virus (BAV) was annotated in the specimens obtained from two pools, and two segments at the 12^th of BAV were obtained by assembly. Two pools were annotated to Kadipiro virus (KDV), and the segment 1^st sequence of KDV was obtained by assembly. Phylogenetic analysis showed that most of the QBV, BAV and KDV strains in this study were closely related to the strains isolated in China in recent years, and both BAV strains belonged to genotype A1. Conclusion This study enriched the understanding of mosquito viromes in China, and revealed the diversity of viruses in mosquitoes and the public health risks of arboviruses such as QBV, BAV and KDV. Thus, our findings may be important evidences in assessment of the risks and control of mosquito-borne infectious diseases in scientific fashion.

Key words: Mosquito, Arthropod-borne viruses, Viral metagenomics, Phylogenetic analysis