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排序方式: 共有10000条查询结果,搜索用时 31 毫秒
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Avian influenza A H5N6 virus is a highly contagious infectious agent that affects domestic poultry and humans in South Asian countries. Vietnam may be an evolutionary hotspot for influenza viruses and therefore could serve as a source of pandemic strains. In 2015, two novel reassortant H5N6 influenza viruses designated as A/quail/Vietnam/CVVI01/2015 and A/quail/Vietnam/CVVI03/2015 were isolated from dead quails during avian influenza outbreaks in central Vietnam, and the whole genome sequences were analyzed. The genetic analysis indicated that hemagglutinin, neuraminidase, and polymerase basic protein 2 genes of the two H5N6 viruses are most closely related to an H5N2 virus (A/chicken/Zhejiang/727079/2014) and H10N6 virus (A/chicken/Jiangxi/12782/2014) from China and an H6N6 virus (A/duck/Yamagata/061004/2014) from Japan. The HA gene of the isolates belongs to clade 2.3.4.4, which caused human fatalities in China during 2014–2016. The five other internal genes showed high identity to an H5N2 virus (A/chicken/Heilongjiang/S7/2014) from China. A whole-genome phylogenetic analysis revealed that these two outbreak strains are novel H6N6-like PB2 gene reassortants that are most closely related to influenza virus strain A/environment/Guangdong/ZS558/2015, which was detected in a live poultry market in China. This report describes the first detection of novel H5N6 reassortants in poultry during an outbreak as well as genetic characterization of these strains to better understand the antigenic evolution of influenza viruses. 相似文献
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Kai WANG Hongze SHAO Zhihua PEI Guixue HU 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2016,78(1):125-128
The aim of this experiment was to develop a loop-mediated isothermal amplification (LAMP)
assay and to research the recent epidemiology of contagious ecthyma in Jilin Province,
China, using the assay. A LAMP assay targeting a highly conserved region of the F1L gene
was developed to detect contagious ecthyma virus (CEV). Three hundred and sixty-five cases
from 64 flocks in 9 different areas of Jilin Province, China, from 2011 to 2014 were
tested using the LAMP assay. The results showed that the sensitivity of the LAMP assay was
100 copies of the standard plasmid, which is 100-fold higher than the sensitivity of PCR.
No cross-reactivity was observed with capripoxvirus, fowlpox virus, foot-and-mouth disease
virus serotype O, foot-and-mouth disease virus serotype Asia I and bluetongue virus. The
average positive rate was 19.73% (72/365), and the positive rate was highest in lambs aged
1–6 months. Our results demonstrated that CEV infection was very widespread in the flocks
of Jilin Province and that the LAMP assay allows for easy, rapid, accurate and sensitive
detection of CEV infection. 相似文献
107.
试验旨在构建能表达牛病毒性腹泻病毒(Bovine viral diarrhea virus,BVDV)E2抗原蛋白的重组乳酸乳球菌(Lactococcus lactis),为进一步研制BVDV乳酸菌口服活载体疫苗奠定基础。将BVDV E2基因克隆后测序,根据乳酸乳球菌的密码子偏嗜性进行优化,再将优化的基因片段插入表达载体pNZ8148中,并电转化乳酸乳球菌NZ9000感受态细胞,构建重组乳酸菌pNZ8148-E2/NZ9000,经1 ng/mL乳链菌肽诱导表达后,对菌体物进行了SDS-PAGE和Western blotting分析。将重组乳酸菌pNZ8148-E2/NZ9000口服免疫6~12月龄健康犊牛,在免疫后不同时间点采集血液样品并分离血清,用间接ELISA方法检测抗体水平。结果显示,PCR扩增到了1 149 bp的目的片段,乳酸菌密码子偏嗜性优化后,GC含量从45.28%变为34.30%。重组质粒pNZ8148-E2经酶切鉴定插入片段与预期大小相符,在菌体裂解物中出现大小约42 ku的条带,与预期蛋白大小一致,且该蛋白可与BVDV E2抗体反应。在免疫犊牛的血清中检测到特异性抗BVDV E2蛋白的抗体。本研究结果表明,表达BVDV E2蛋白的重组乳酸菌口服免疫可诱导犊牛产生特异性的体液免疫反应,该重组菌具有较好的免疫原性。 相似文献
108.
Chun-Zhi REN Wen-Yue HU Jun-Cheng LI Ying-Hong XIE Ni-Na JIA Jun SHI Ying-Yi WEI Ting-Jun HU 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2020,82(12):1781
Pseudorabies virus (PRV) infection leads to severe inflammatory responses and tissue damage, and many natural herbs exhibit protective effects against viral infection by modulating the inflammatory response. An ethyl acetate fraction of flavonoids from Polygonum hydropiper L. (FEA) was prepared through ethanol extraction and ethyl acetate fractional extraction. An inflammatory model was established in RAW264.7 cells with PRV infection to evaluate the anti-inflammatory activity of FEA by measuring cell viability, nitric oxide (NO) production, reactive oxygen species (ROS) release, and mRNA expression of inflammatory factors, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2). Its functional mechanism was investigated by analyzing the phosphorylation and nuclear translocation of key proteins in the nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways. Our findings indicate that PRV induced inflammatory responses in RAW264.7 cells, and the responses were similar to that in lipopolysaccharide (LPS)-stimulated cells. FEA significantly suppressed NO synthesis and down-regulated both expression and secretion of COX-2, iNOS, and inflammatory cytokines (P<0.05 or P<0.01). FEA also reduced NF-κB p65 translocation into the nucleus and decreased MAPK phosphorylation, indicating that the NF-κB/MAPK signaling pathway may be closely related to the inflammatory response during viral infection. The findings suggested the potential pharmaceutical application of FEA as a natural product that can treat viral infections due to its ability to mitigate inflammatory responses. 相似文献
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甘蔗花叶病广泛存在于我国甘蔗种植区,严重影响甘蔗产业的高质量发展。近年来甘蔗线条花叶病毒在蔗区肆虐,尽管针对其的血清学检测技术已经建立,但是快速、准确、高通量的检测方法亟待发掘。本研究制备了SCSMVCP的抗血清,特异性高,与引起甘蔗花叶病的另两种病原 (高粱花叶病毒和甘蔗花叶病毒) 间没有血清学交叉反应。基于该多克隆抗体,建立了直接抗原包被的ELISA、斑点杂交、Western blot和基于多抗的免疫试纸条检测技术。开发的免疫试纸条检测技术能快速、准确、高通量应用于田间病毒鉴定。本文提供了基于血清学的快速、准确、高通量,且便捷的甘蔗线条花叶病毒检测技术,有助于我国蔗区甘蔗花叶病的监测与防控。 相似文献