Identification And Full-length Genome Analysis Of LCMV In Ticks

Ticks,a very important pathogen-vector arthropods with high species-diversity and wide geographical distribution,can transmit various zoonoses and present great harm to human and animal health.Epidemic tick-borne disease in northeast China maily includs Lyme disease,babesiosis,spotted fever rickettsiosis,tick-borne encephalitis,fever with thrombocytopenia syndrome.The clinical symptoms of most tick-related communicable infectious diseases are not typical,and they are easily misdiagnosed and missed in clinical practice.Tick-borne transmission disease has now become the focus of researchers.Due to the constant progress of molecular biology technology and the sustained improvement of statistical methods,the ability of pathogen identification and clinical diagnosing has been greatly improved.Lymphocytic choriomeningitis virus(LCMV)is a kind of arena virus within the geneus of sandviridae belonging to the order of single negative-strand RNA virus,and is the earliest discovered virus of the Shapiroviridae family.Rodents are the natural host of LCMV.Since 1933,a number of LCMV infection cases has been reported with exposure of rodent contacts,rodent excretions,rodent bites,or arthropods bitten.LCMV can cause asymptomatic persistent chronic infection after infection in humans.It will lead to serious meningitis death,Higher death rate after a patient infected with the immunodeficiency virus.As early as the 1970 s,there were reports of 65 cases of chronic lymphocytic meningitis after being bitten.In the past 50 years,no ticks-related human LCMV infection was reported.In this study,ticks distributed in Dunhua City and Jingxin Town in Jilin Province were collected in 2015.The mixed samples of tick are processed and subjected to metagenomic sequencing.indicating LCMV infection in Jilin Province.534 ticks of four species: D.nuttalli(43.1%)D.silvarum(38.4%),H.longicornis(11.4%),and I.persulcatus(7.1%)were collected and underwent LCMV identification showing a positive.rate of 4.46% in Jilin Province.5.6% in Jingxin town and 1.5% in Dunhua City,respectively.The infection rates of LCMV in H.longicornis,D.nuttalli,D.silvarum,and I.persulcatus were: 12.2%,2.5%,4.4%,and 2.5%,responsibly,highest in H.longicornis.For genome-wide analysis,S and L fragments showed sequence similarity of 86% and 82.2% with those from type Ⅰ LCMV.There are less homology found with type II,type III and type IV LCMVs.Phylogenetic analysis showed that the LCMVs identified in this study belonged to type I and consititute a separate clade.In this study,we firstly identified the prevalence of LCMV infection in ticks.All the four tick species collected in Dunhua City and Jingxin Town of Hunchun City,Jilin Province,most prevalent in H.longicornis,were found positive for LCMV Phylogenetic analysis identified the LCMV in this study as type 1 lineage,indicating potential spillover of LCMV infection to humans.In the present study,we also determined the LCMV infection rate in various tick species in northeastearn China.Providing a scientific support for prevention and control tick-borne LCMV in this area.