Liao Ning Virus Investigation In Liaoning,Xinjiang And Yunnan Provinces And Molecular Characterization Of Liao Ning Virus Isolates

Liao Ning virus (LNV), the member of Reoviridae family Seadorna genus, is the non-enveloped virus, including12segments. Liaoning virus was first isolated from Aedes dorsalis in Heishui town, which located in the nearby Baicheng in Gilin province in1997. After that, the virus was successively isolated from Aedes dorsalis, Culex modestus and Anopheles in Xinjiang, Shanxi, Qinghai and Gansu in China. Presently, the research results show that LNV is divided into genotype Ⅰ and genotype Ⅱ. The representative strain is NE97-12and NE97-31, respectively. The genotype Ⅱ LNV was disappeared since it was isolated from Gilin Province in China in1997. This study conducted Liao ning virus investigation in Liaoning, Xinjiang and Yunnan provinces, and analyzed the molecular characteristics of LNV to further understand the distribution pattern and the molecular characteristics of LNV.1. Liaoning Virus investigation in Liaoning, Xinjiang and Yunnan provincesMosquito samples were collected by using mosquito-lured lamp in Liaoning, Xinjiang and Yunnan Provinces in season suitable for breeding. The collected mosquito samples were treated with classification of tubing, cold chain transportation and liquid nitrogen preservation. All the virus isolates were obtained by inoculating the grinded supernatants onto C6/36and BHK-21cells followed by observing cytopathic effect (CPE). The positive isolates were identified by molecular biological methods.3292mosquito samples were collected in Liaoning province in August2012, in which the main species is Anopheles sinensis (2552,77.5%).2Liao ning viruses were isolated from Anopheles sinensis and Aedes dorsalis, respectively.26155mosquito specimens were collected in Kashgar region in Xinjiang province from May to August in2011, and19Liaoning viruses were isolated from Ae.flavidorsalis, Aedes caspius, and Culex pipiens.13337mosquito samples covering5genus and29species were collected in Xishuangbanna in Yunnan province from April to August in2011, in which Culex tritaeniorhynchus was the main species(10667). No Liao ning virus was detected or isolated from these samples. There was also no nucleic acid positive results for other arboviruses, including Japanese encephalitis virus, Banna virus, Alphavirus and Orbivirus. In this study, The rusult of Xishuangbanna in Yunnan province is consistent with previous result that Liao ning virus only distributes in the high latitudes. The isolates from Xinjiang province had the more homology with NE97-12than NE97-31. The isolated from Liaoning province had the closest homology with NE97-31. The most important thing is that it’s the first time that Liao ning virus was isolated from the Culex pipiens, Ae.flavidorsalis, Aedes caspius and Anopheles sinensis.2. Molecular Characterization of Liao ning Virus isolated in China.The new Liaoning virus isolates from Xinjiang and Liaoning provinces had been gathered and sequenced on segment10and segment12by molecular biology. This study had also identified and studied the molecular characterizations of Liao ning viruse by using bioinformatic software. The phylogenetic analysis suggested that Liao ning viruses collected in Xinjiang belong to genotype Ⅰ. And LNV isolates from Liaoning province are clustered into genotype Ⅱ, which is the first time this virus was isolated in Liaoning province. It is the first time that genotype Ⅱ virus was isolated since1997. It’s confirmed that evolution characteristics of LNV isolates from different region have it’s own feature.The Significance of this StudyWe conducted a LNV investigation in Liaoning, Xinjiang and Yunnan provinces. It’s the first time that LNV was isolated in Liaoning province. Genotype Ⅱ virus was isolated at the first time since1997. Besides, several LNVs were isolated in Xinjiang province. The results show us that LNV is epidemic in local mosquito and further confirmed that the virus is distributed in high latitudes. This study enriched the research on LNV and also provide important information to understand the genetic variation of LNV. The study is the continuous research based on investigating local arboviruses. It will supply important scientific data for finding the genomic changes of LNV and the relationship with the local disease epidemiology, and has an important significance for disease control and prevention.