Until the recent emergence/re-emergence of human-pathogenic viruses in ticks, tick-borne viruses have been neglected as causative agents of human disease (particularly in China). To gain insight into the diversity of tick-borne viruses in Xinjiang Uygur Autonomous Region (northwestern China), we conducted illumina deep sequencing-based screening for virus-derived small RNAs in field-collected Ixodes persulcatus ticks. We found 32, 631 unique virus-matched reads. In particular, 77 reads mapped to the tick-borne group within the genus of Flavivirus, and covered 3.8%-2.4% viral genomes. In addition, 32 unique reads were specific to the Siberian subtype of tick-borne encephalitis viruses (TBEV-Sib) which have never been reported in Chinese TBE loci. We confirmed the potential existence of TBEV-Sib by amplification (using reverse transcription-polymerase chain reaction) of genomic fragments from the envelope gene or 3' genomic terminus from the pools of examined ticks. Both sequences demonstrated high homology to TBEV-Sib strains attached geographically to southern Siberia with nucleotide identity of 97.2%-95.5% and aminoacid identity of 99.4%-98.3%, respectively. In conclusion, we report, for the first time, detection of TBEV-Sib in the natural TBE loci of China. These novel data may provide genetic information for further isolation and epidemiologic investigation of TBEV-Sib.
Animals ; Arachnid Vectors ; virology ; China ; Encephalitis Viruses, Tick-Borne ; classification ; genetics ; isolation & purification ; Encephalitis, Tick-Borne ; transmission ; virology ; Genome, Viral ; Humans ; Ixodes ; virology ; Molecular Sequence Data ; Phylogeny

OBJECTIVETo study the proliferation and location of hantaan virus (HV) in gamasid mites and chigger mites.

METHODSHV RNA in gamasid mites and chigger mites were detected by reverse transcription, polymerase chain reaction (RT- PCR) and in situ hybridization.

RESULTSThe smallest quantity of mite from which HV RNA could be detected was 5 mites group. The titers of -and proliferated in mites HV RNA could be found in ovary cells and dug cells of gamasid mites and chigger mites by in situ hybridization.

CONCLUSIONSThe results showed that HV could be trans-stadially transmitted and proliferated in mites, and HV always located in ovary and dug organs of mites. These results provide direct evidence at molecular level for the role of gamasid mites and chigger mites as vectors in transmission of HV.

Animals ; Arachnid Vectors ; Cercopithecus aethiops ; Female ; Hantaan virus ; genetics ; growth & development ; isolation & purification ; Humans ; In Situ Hybridization ; Larva ; virology ; Mites ; virology ; Nymph ; virology ; Ovary ; Polymerase Chain Reaction ; RNA, Viral ; analysis ; Reverse Transcriptase Polymerase Chain Reaction

To understand the maintenance and transmission of SFTS virus, the potential vector ticks were collected from sheep, cattle and dogs in the endemic areas of SFTSV in Shandong Province. Among the collected ticks, the dominant species was H. longicornis ticks. Real-time PCR for RNA detection, virus isolation and characterization, genomic sequencing, phylogenetic and antigenic analysis were performed in this investigation. The results showed that the SFTS viral RNA was detected in 2.14% H. longicornis, and a SFTS virus was isolated from one of viral RNA positive ticks collected from sheep. Whole genome analysis of the SFTSV isolates with 11 human-origin SFTS virus revealed a highly pairwise similarity, and the growth curve analysis showed nearly identical in virus yield and the dynamic of virus reproduction compared to human derived viral isolates. Immunofluorescence and neutralization test showed identical serological reaction character of the two different origin viral strains. In this study, the characters of a SFTSV isolate was firstly described, which suggested that the tick species H. longicornis acting important vector role in the transmission of SFTS virus.
Animals ; Animals, Domestic ; parasitology ; Arachnid Vectors ; virology ; Bunyaviridae Infections ; transmission ; virology ; Cattle ; Cell Line ; Dogs ; Humans ; Livestock ; parasitology ; Molecular Sequence Data ; Phlebovirus ; classification ; genetics ; isolation & purification ; Phylogeny ; Sheep ; Ticks ; virology

The prevalence of tick-borne encephalitis virus (TBEV) in southern Korea was determined by collecting ticks using tick drags. A total of 4,077 of 6,788 ticks collected were pooled (649 pools) according to collection site, species, and developmental stage and assayed for TBEV. The TBEV protein E and NS5 gene fragments were detected using RT-nested PCR in six pools of nymphs collected from Jeju Island (2,491 ticks). The minimum field detection rates for TBEV were 0.17% and 0.14% for Haemaphysalis longicornis and Haemayphysalis. flava nymphs, respectively. The 252 bp NS5 and 477 bp protein E gene amplicons were sequenced. Phylogenetic analysis showed that the NS5 and protein E genes of the Jeju strain were clustered with Western subtype (98.0% and 99.4% identity, respectively). The Western subtype of TBEV is endemic in Korea, including Jeju Island. The study of vector and zoonotic host susceptibility to TBEV is required to better understand its potential impact on public health.
Animals ; Arachnid Vectors/*virology ; Base Sequence ; DNA Primers/genetics ; Encephalitis Viruses, Tick-Borne/classification/*genetics ; Encephalitis, Tick-Borne/*epidemiology ; Molecular Sequence Data ; *Phylogeny ; Prevalence ; Republic of Korea/epidemiology ; Reverse Transcriptase Polymerase Chain Reaction ; Sequence Analysis, DNA ; Ticks/*virology ; Viral Envelope Proteins/genetics