China ; Coltivirus ; Encephalitis, Tick-Borne ; virology ; Humans

OBJECTIVEThe purpose of this article is to review the developments of studies of Coltivirus in China.

DATA SOURCESThe data used in this review was obtained mainly from the studies of Coltivirus reported from 1990 to 2003 in China.

STUDY SELECTIONRelevant articles on studies of Coltivirus in domestic and foreign literature were selected.

DATA EXTRACTIONData were maily extracted from the articles which are listed in the reference section of this review.

RESULTSMany Coltiviruses have been isolated not only from blood samples of patients with unknown fever or from cerebrospinal fluid of patients with encephalitis in Xishuangbanna area in Yunnan province, but also from mosquitoes collected in many areas in China. In some patients diagnosed as Japanese encephalitis or unknown fever, an increase of Coltivirus IgG antibody of fourfold, or more, has been detected using ELISA. Similarly, Coltivirus IgM antibody was positive in some patients with Japanese encephalitis or viral encephalitis. From most Chinese patients, except the northeastern, the isolates of Coltiviruses belong to subgroup B2, according to RT-PCR amplification of the ninth and twelfth segments of the isolates and sequence analysis of their amplicons. Some biological properties of Chinese Coltiviruses isolates are different from that of North American Coltiviruses.

CONCLUSIONSThe isolates of Coltiviruses from Chinese patients are one of the common agents causing viral encephalitis and unknown fever in summer-autumn season. It might be an important public health problem due to its high isolation rate and wide distribution in China. Mosquito is the main transmission vector of the virus.

Animals ; Antibodies, Viral ; blood ; Coltivirus ; classification ; genetics ; immunology ; isolation & purification ; Genotype ; Humans ; Rats

OBJECTIVETo classify the Chinese isolates of Coltiviruses.

METHODSThree sets of primers were selected among them two were specific to the 9th and 12th segments of subgroup B2, and one was for the 12th segment of subgroup B1-All the Chinese isolates of Coltivirus selected in the experiment were classified according to the lengths of different amplicons of the reverse transcriptase-polymerase Chain reaction (RT-PCR). The homogenicity of the nucleic acids of the isolates BJ95-75 and YN-6 was also compared with other Coltivirus strains belonging to subgroup B2.

RESULTSWith the primers 12-854-S/12-B2-R, which were specific to the 12th segment of Coltivirus subgroup B2-850 bp amplicons were obtained from Beijing isolate BJ95-75 and all the Yunnan isolates such as YN-6, -67-1, -68-1, -69, -70-1, -70-2, -90, -92-2, -93 of Coltivirus 492 bp DNA fragments were also amplified from all of them with the segment 9th specific primers 9-JKT-S/9-JKT-R. However no positive results were obtained from Northeast isolates NE97-12, NE97-31 and control viruses YN-99(Orbivirus),YN-151-1(JEV) with the same two sets of primers. With 12-B1-S/12-B1R primers specific to the 12th segment of subgroup B1, no amplicons of right length were obtained from any of the Chinese isolates of Coltivirus and the control viruses. When compared the nucleic acid sequences of BJ95-75 and YN-6 with other Coltivirus strains such as Bannavirus, JKT6423, JKT6969, JKT7043, the amplicons from segment 12th of these two strains had more than 89.4% homology with the other strains, especially to the earlier Chinese isolate Bannavirus, the homolog was more then 98.9%. Nearly 96.5% and 99.2% of the nucleic acids of the amplicons from segment 9th of the two strains were being homologous to Bannavirus and about 84.0% to JKT6423, which had been classified into type B2a. But the maximal homogenicity was about 53% when compared with the other two coltivirus strains. JKT6969 and JKT7043 which had been classified into type B2b.

CONCLUSIONGenotyping the recent Chinese isolates of coltivirus for the first time in our country. Most of the Chinese isolates belong to subgroup B2, more exactly type B2a. The Northeast isolates NE97-12 and NE97-31 were not correctly grouped with the available primers.

Animals ; Base Sequence ; China ; Coltivirus ; classification ; genetics ; isolation & purification ; Culicidae ; virology ; Genotype ; Reverse Transcriptase Polymerase Chain Reaction ; Sequence Homology, Nucleic Acid

BACKGROUNDTo study the molecular characteristics of YN92-4 strain isolated from mosquitoes in Yunnan Province and define its classification.

METHODSThe S segment of YN92-4 strain was amplified and sequenced by 2 different sets of primers. The phylogenic tree of S fragment was constructed by Phylip bio-software. The amino acid sequences of N and NSs proteins were also studied.

RESULTSYN92-4 strain could be amplified by 2 sets of primers respectively, S segment showed a highest homology with Batai virus (X73464), reached 96.4%, the homology of protein N and NSs amio-acid sequence with Batai virus was 99.1% and 98% respectively.

CONCLUSIONThe YN92-4 strain belongs to Batai virus, this is the first report of molecular biological identification of Batai virus in China.

Amino Acid Sequence ; Animals ; Bunyamwera virus ; classification ; genetics ; isolation & purification ; China ; Culicidae ; virology ; DNA, Complementary ; chemistry ; genetics ; Molecular Sequence Data ; Phylogeny ; RNA, Viral ; genetics ; isolation & purification ; Reverse Transcriptase Polymerase Chain Reaction ; Sequence Analysis, DNA ; Sequence Homology, Amino Acid

BACKGROUNDTo study the arboviruses carried by mosquitoes collected in Hebei Province.

METHODSSamples were collected from mosquito active sites and stored in liquid nitrogen till use. Pools of 20 to 30 mosquitoes were ground after sterilization, centrifugal supernant was inoculated onto C6/36 cell, cytopathic effect was observed for three sequential passages. Positive isolates were identified by IFA and RT-PCR.

RESULTSTotally 1310 mosquitoes were collected from two villages of She county, Hebei province. They were divided into 46 pools and ground respectively. Thirteen positive isolates were obtained. Two isolates reacted with alphaviral antibodies and were amplified by alphaviral primers, nucleotide sequence showed the highest homology (98%) to Getah virus (AY702913.1), so the two isolates were identified as Getah virus.

CONCLUSIONGetah virus was isolated from mosquitoes in Hebei Province. This is the first report of isolating Getah virus from inland of China.

Animals ; Arboviruses ; classification ; genetics ; isolation & purification ; Cell Line ; Cluster Analysis ; Culicidae ; virology ; Phylogeny ; Reverse Transcriptase Polymerase Chain Reaction ; Sequence Analysis, DNA

OBJECTIVETo investigate the epidemic state of arboviruses in the downstream area of Lancang river in Yunnan province.

METHODSMosquitoes were collected from Lancang river downstream area (including Lancang county and Simao city) during summer in 1998 and stored in liquid nitrogen after classification. The mosquito pools were homogenized and centrifuged, then the supernatant was inoculated into C6/36 cells for virus isolation. New isolates were identified by neutralization test(NT), ELISA, immunofluorescence assay(IFA) and polyacrylamid gel electrophoresis(PAGE).

RESULTSTotally 22 isolates of arbovirus were obtained from 233 mosquito pools by inoculation of C6/36 cells and positive rate of the isolation was 9.4%. Ten strains were resistant to both ether and 5 prime-IDU. So they were non-enveloped double-stranded (ds) RNA virus. Twelve segmented RNAs were shown by PAGE and PAGE profiles from the ten strains were 6-6 with minor variation. The isolates can be neutralized by immunized mouse ascites fluid of BJ95-75 strains of coltivirus by NT, and reacted with monoclonal antibody against BJ95-75 by ELISA. These viruses were identified as coltivirus. Nine isolates were sensitive to ether and resistant to 5 prime-IDU. So they were non-enveloped RNA viruses. PAGE showed 10 segmented RNA, and they were identified to be orbiviruses. Three isolations were sensitive to ether. One of them can be neutralized with JEV A2 strain antibody by NT and was positive to the homologous antibody by IFA. It was identified being strain of JE virus. One strain(YN92-4) can be reacted with anti-bunyavirus group specific immune ascites fluid by both IFA and ElISA, but reacted neither with anti-alpha virus group, nor with anti-flavivirus group JE virus ascites fluid. The virions are spherical and about 87 nm in diameter with surface projections by negative staining. Conclusion Twenty-two isolates have been obtained from wild caught-mosquitoes of Lancang river down-stream area in Yunnan province. Among them ten, nine, one and one were identified as coltivirus, orbivirus, JE virus and bunyavirus, respectively. One is under identification. This is the first report on bunyavirus isolated from mosquitoes in China.

Animals ; Arboviruses ; classification ; isolation & purification ; China ; Coltivirus ; isolation & purification ; Culicidae ; virology ; Encephalitis Virus, Japanese ; isolation & purification ; Insect Vectors ; virology ; Orbivirus ; isolation & purification ; Orthobunyavirus ; isolation & purification