OBJECTIVETo investigate the distribution patterns of mosquito and mosquito-borne viruses in Dehong prefecture, Yunnan province, China.

METHODSMosquito samples were collected using the mosquito traps from five counties of Dehong prefecture on July, 2007 and 2010. Mosquito were cell cultured for viral isolation, and positive isolates were identified using RT-PCR and sequence analysis.

RESULTSA total of 43 634 mosquito comprised of 29 species representing six genera were collected. Culex tritaeniorhynchus and Anopheles sinensis comprised 78.69% and 14.77% of the total. Six strains of viruses were isolated from the mosquito pools. RT-PCR and phylogenetic analysis revealed three strains from Cx. tritaeniorhynchus, identified as genotype I Japanese encephalitis virus (JEV). One strain was identified from Cx. tritaeniorhynchus, as Getah virus (GETV). Two strains isolated from Cx. tritaeniorhynchus and Anopheles vagus were identified as Culex pipiens pallens Densovirus (CppDNV).

CONCLUSIONCx. tritaeniorhynchus had been the major species of mosquito and mainly transmitting vector of mosquito-borne viruses in Dehong prefecture. Genotype I JEV, GETV and CppDNV were the vectors causing transmission of mosquito-borne diseases in this area. Data from phylogenetic analysis showed that these newly discovered isolates seemed to have had close relationship with those viruses previously circulating in Yunnan and other provinces of China.

Alphavirus ; isolation & purification ; Animals ; Arboviruses ; classification ; isolation & purification ; China ; Culicidae ; virology ; Disease Vectors ; classification ; Encephalitis Virus, Japanese ; isolation & purification

OBJECTIVETo investigate arboviruses in Wenshan and Hekou county which are the Sino-Vietnam frontier regions of Wenshan, Yunnan province, China.

METHODSIn September 2007, 6091 Culicines, 1334 Anophelines, 848 Aedes vexans and 53 Armigeres obturbans were collected from 5 field sites. Mosquitoes were collected and stored in liquid nitrogen after classification. The mosquito pools were homogenized, and centrifuged, then the supematant was inoculated onto C6/36 and BHK-21 cells, and the viral isolates were identified by serological and molecular biological methods.Sequence alignment and phylogenetic analysis on the viral isolates were carried out using Clustal X 1.85, GENEDOC and MEGA4 software.

RESULTSA total of 4 pairs of virus isolated with C6/36 cells cytopathic effect were observed, and other mosquito species have not cytopathic effect.Strain WS0704-2 was Banna virus which identified by antibody response and PCR. Strain WS0704-1, WS0708-1, WS0708-2 were Culex pipens pallens densovirus (CppDNV) which identified by PCR. The phylogenetic analysis the 12th segment showed significant difference between the new Banna virus and other strains isolated in China.

CONCLUSIONThere are many mosquito vectors in frontier regions (China and Vietnam) of Wenshan in Yunnan province of China, and mosquito-borne arbovirus, such as BAV were isolated here.

Animals ; Arboviruses ; classification ; genetics ; isolation & purification ; China ; Culicidae ; virology ; Densovirus ; genetics ; isolation & purification ; Phylogeny ; Sequence Alignment ; 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

BACKGROUNDMosquitoes were collected in Heilongjiang province in 2002, four virus strains were isolated by inoculation of homogenates onto BHK cell lines. The viruses were identified. Multiple alignment and phylogenetic analysis were carried out by Clustal X (1.8) program.Amino acid (AA) analysis was carried out by GENEDOS (3.2).

RESULTSBiological characters of four newly isolated strains were examined and it was found that all of them could produce cytopathogenic effect (CPE) in BHK cells, killing sucking mice. Serological tests showed that all of these stains reacted positively to JEV antibodies. PrM and E gene regions were amplified and sequenced. Phylogenic analysis showed that all the newly isolated JEV strains belong to genotype III. Using the vaccine strains (SA14-14-2) as control, analysis of the E gene of the new strains and two JEV strains (47, Ha-3) isolated previously from Heilongjiang province showed that these new strains' nucleotide sequence had a homology of up to 99.9% and the amino acid sequence homology up to 99.8%, respectively. Compared with the standard JE vaccine strain SA-14-14-2 and the four new strains, the nucleotide sequence homology was 97.3% and amino acid sequence homology was between 96.8% and 97.0%, respectively. Compared with vaccine strain, there were seven common variations in all the four newly isolated strains.

CONCLUSIONFour JE virus strains were isolated in Heilongjiang province. As compared to the vaccine strain, six variations were found in the newly isolated strains at the eight sites relevant to the virulence of the virus.

Animals ; Arbovirus Infections ; virology ; Arboviruses ; classification ; genetics ; isolation & purification ; Cell Line ; Culicidae ; virology ; Genotype ; Mice ; Molecular Sequence Data ; Phylogeny

OBJECTIVETo investigate the natural infection and genotype of Japanese encephalitis virus in mosquitoes and swine in some areas of Zhejiang province.

METHODSSamples of mosquitoes and sera of swine were collected in three counties (Xianju, Longquan and Cixi) of Zhejiang province from May to October in 2007. 10 662 mosquitoes were collected during 2007, of which, C.pipiens pallens and C.quinquefasciatus were the most dominant species and 204 pig serum samples were detected. Japanese encephalitis virus in mosquitoes were detected by virus isolation and real time RT-PCR. The antibody against Japanese encephalitis virus in swine was detected by ELISA. The isolated strain were identified by real time RT-PCR. The PrM gene of the isolated strain was amplified by RT-PCR. Three strains were typed by the gene of PrM.

RESULTSSeven positive mosquitoe samples were identified by real time RT-PCR. Three strains were isolated and identified by real time RT-PCR. The PrM gene was cloned and sequenced. The phylogenetic analysis showed that three isolates belong to genotype I of Japanese encephalitis virus. Of 204 swine serum samples, 121 positive samples were identified positives. Above 50% sera samples from swine were positive in June.

CONCLUSIONThe vector of Japanese encephalitis virus existed and carried the Japanese encephalitis virus in these areas of Zhejiang province. Three strains of Japanese encephalitis virus were isolated from mosquito pools collected in Zhejiang province. It should be the first isolation of genotype I Japanese encephalitis virus in Zhejiang province in recent years.

Animals ; Antibodies, Viral ; blood ; Arboviruses ; classification ; isolation & purification ; China ; Culicidae ; virology ; Disease Vectors ; Encephalitis Virus, Japanese ; classification ; genetics ; isolation & purification ; Genotype ; Swine ; virology

Multiplex reverse transcription-polymerase chain reaction (mRT-PCR) is currently available in virus detection and defined as the simultaneous amplification of two or more DNA/RNA targets in a single reaction vessel. In this study, we attempted to modify the conventional mRT-PCR technique on a basis of GenomeLab Genetic Analysis System (GeXP). Initially, we optimized the analytical validation of the GeXP analyzer and its design of workflow and simultaneously detected eight arboviruses that related to epidemic encephalitis by verifying the specificity of mRT-PCR with Japanese encephalitis virus(JEV) cell cultures and positive strains identified previously and determining the sensitivity with in vitro-transcribed RNA of serial dilutions. The GeXP system after optimization could amplify the specific fragments related to the viruses and exposed specifically a total of 13 target genes out of eight types of arboviruses at the level of 10(2) copies/microL, and the findings suggest that the novel protocol we developed can be high-throughput and highly specific and sensitive as well as quickness in screening of the encephalitis viruses, and is promising in detection of encephalitis-associated viruses for molecular epidemiological studies.
Arboviruses ; genetics ; isolation & purification ; Encephalitis Virus, Japanese ; genetics ; Encephalitis Viruses ; genetics ; isolation & purification ; Reverse Transcriptase Polymerase Chain Reaction ; methods ; Sensitivity and Specificity

Culicoides biting midges were collected on three cattle farms weekly using light traps overnight from May to October between 2010 and 2011 in the southern part of Korea. The seasonal and geographical abundance of Culicodes spp. were measured. A total of 16,538 biting midges were collected from 2010 to 2011, including seven species of Culicoides, four of which represented 98.42% of the collected specimens. These four species were Culicodes (C.) punctatus (n = 14,413), C. arakawae (n = 1,120), C. oxystoma (n = 427), and C. maculatus (n = 318). C. punctatus was the predominant species (87.15%).
Animals ; Arboviruses/isolation & purification ; Cattle ; Cattle Diseases/transmission/*virology ; Ceratopogonidae/*classification/*physiology ; Insect Vectors/physiology ; Population Density ; Republic of Korea/epidemiology ; Species Specificity ; Time Factors

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

Objective: To investigate the distribution patterns of mosquitoes, midges and related arboviruses in Sichuan province. Methods: Blood-sucking insects were collected from houses and pens, using the ultraviolet lights. Mosquito samples were classified according to morphologic characteristics and then stored at liquid nitrogen. All samples were incubated with BHK-21 and C6/36 cells for virus isolation and then detected for their viral genes. Sequences of the virus were identified and analyzed by molecular biological software, such as BioEdit 7.0.5.3, MEGA 6.0. Results: In total, 17 019 mosquitoes from 3 genera and 4 species and 12 700 midges were collected from the southeast regions of Sichuan province in 2016 and 2017. Among them, 79.4% (13 519/17 019) belonged to Culex tritaeniorhynchus with 11.1% (1 897/17 019) as Armigeres subalbatus, 5.5% (930/17 019) were Anopheles sinensis and 4.0% (673/17 019) were Anopheles sinensis 3 virus strains that isolated from Culex tritaeniorhynchus were identified as typeⅠ Japanese encephalitis virus. Seven pools of mosquitoes isolated from Hejiang county were identified Japanese encephalitis virus gene positive through PCR amplification. With 4 pool midges were detected positive for Akabane virus through PCR gene amplification while midges samples didn't have virus isolates. Conclusions: Culex tritaeniorhynchus appeared the predominant species in the southeast regions of Sichuan. Japanese encephalitis virus transmitted by mosquitoes and Akabane virus by midges were prevalent in southeast Sichuan province.
Animals ; Arboviruses ; Culicidae ; Encephalitis Virus, Japanese/isolation & purification* ; Encephalitis, Japanese/diagnosis* ; Genes, Viral ; Nucleic Acid Amplification Techniques ; Phylogeny ; Polymerase Chain Reaction

BACKGROUNDTo disclose the species and distribution of tick-borne arboviruses in the southern part of Xinjiang.

METHODTotally 5045 ticks were collected from 36 collecting sites of 23 places in the southern Xinjiang, which were made into cDNA pools with pd(N)6 primer through RT-PCR method. Then PCR was used to detect viral nucleotide sequence from cDNA.

RESULTSAll 34 cDNAs showed negative to flavivirus and California serogroup virus primers; but nairovirus and primers derived from Xinjiang hemorrhagic fever virus had amplified and yielded some obvious bands corresponding to the nucleotide sequences of Xinjiang hemorrhagic fever virus. A phylogenetic analysis was done to the obtained partial sequences of L and S segments.

CONCLUSIONNucleotide sequences of Neither flaviviruses nor California serogroup viruses were detected from the samples. However partial L segment sequence was first reported in China. Phylogenetic analysis of partial L and S segments disclosed the molecular characteristic of Xinjiang hemorrhagic fever virus.

Animals ; Arboviruses ; classification ; genetics ; isolation & purification ; China ; Hemorrhagic Fever Virus, Crimean-Congo ; classification ; genetics ; isolation & purification ; Phylogeny ; Reverse Transcriptase Polymerase Chain Reaction ; Sequence Analysis, DNA ; Tick-Borne Diseases ; virology ; Ticks ; virology