Molecular Epidemiology Of Tick-borne Viruses In Part Regions Of Xinjiang And Inner Mongolia

As the second-largest vector of arboviruses after mosquitoes,ticks can carry more than 160 viruses,20%-30%of which are pathogenic to humans or livestock.To explore the overall situation of tick-borne viruses in Xinjiang and Inner Mongolia,and to investigate whether there are viruses of zoonotic diseases or potential pathogenicity,ticks were collected from four areas of Xinjiang(Qinghe,Fuyun,Fuhai,and Wusu)and four areas of Inner Mongolia(Siziwang Banner,the junction of Alxa left banner,Right Banner and left and Right Banner).The viromics and molecular epidemiology of ticks collected were studied by using metatranscriptomics and bioinformatics and related technologies.The results are as follows:1.Six species of ticks belonging from two genera were collected in Xinjiang,with 1,328 ticks in total,including Hyalomma asiaticum,Dermacentor silvarum,Dermacentor nuttalli,Hyalomma scupense,Dermacentor marginatus,and Hyalomma dromedarii;a total of 1,308 ticks were collected from two genera and five species similar to Xinjiang except for Hyalomma scupense in Inner Mongolia.2.A total of 71 8,115 virus reads were obtained from 8 tick metatranscriptome groups in Xinjiang and Inner Mongolia.The results were annotated as 17 known viruses of family and bunyavirales,including double-stranded RNA(dsRNA)virus,ssRNA(-),and ssRNA(+)virus.The natural hosts of viruses include vertebrates,including mammals,arthropods,plants,bacteria,and fungi.Alpha and beta diversity analysis showed that there was no difference in virus richness between Xinjiang and Inner Mongolia.Although there was a specific difference in virus diversity,there was no statistical significance.However,the Siziwangqi group in Inner Mongolia is different from the other seven groups in diversity and virus species composition.3.A total of 21 viruses of 7 families and some unclassified viruses were obtained from 8 tick transcriptome libraries,including nine identified viruses and 12 new viruses.The phylogenetic tree showed that most RNA viruses clustered in known viral genera,and some viruses showed unique evolutionary patterns.A new sandfly virus-Alxa tick phlebovirus,was identified from ticks in Alxa League.The virus was most closely related to the Makuwu virus in evolution and was closer to the ancestor of phlebovirus in evolution origin.This study firstly found Severe fever with thrombocytopenia syndrome virus(SFTS V)in the Siziwang Banner of Inner Mongolia.According to the phylogenetic analysis,the L and M fragments of the strain were not clustered with the strains found,while the s fragment was clustered with the B type in Japan.6.A total of 3,568,561 reads were obtained from the tick metagenome in Inner Mongolia,of which 12,931(0.36%)were obtained.The sequences annotated as viruses belong to 20 known viral families and unclassified virus information,including dsDNA virus,ssDNA virus,and single-stranded RNA(ssRNA)virus.The natural hosts of the virus include vertebrates,arthropods,plants,and phages.A circovirus with a length of 2,042 nt was amplified by reverse semi-nested PCR in Inner Mongolia ticks.The virus was found to be a pigeon circovirus by phylogenetic analysis and homology comparison analysis.The above studies have characterized the distribution and diversity of tick viruses in these areas,clarified the evolution of tick arboviruses in the virus evolution process,and revealed that some tick arboviruses might spread across regions and species.These studies are as follows:The background of ticks carrying viruses in Xinjiang and Inner Mongolia,China,and the prevention and control of the prevalence and spread of new viruses provide critical primary data.