virulent strain 中文意思是什麼
virulent strain
解釋
強毒株-
In recent years, the outbreak of nd appear some new characters, it is reported that the amount of immunity defeat on nd increased, even chicks with high hi titer can be infected by ndv virulent strain. the gene - engineering vaccine is badly needed to control nd outbreak. so newcastle disease virus strain b95, a naturally avirulent and heat stable strain, was introduced from australia
新城疫是國際獸疫局公布的16種烈性傳染病之一。近年來，新城疫的爆發出現了許多新特點，免疫失敗報道增多，甚至抗體水平較高的雞群也發病。為控制新城疫的爆發，急需研製基因工程苗。 -
From dead chickens, one virrus was isolated by using eggs and chicken embryo fibroblast. lt was able to agglutinate chicken ' s erythrocytes and this heamagglutination could be inhibited by newcastle disease antiserum. this strain ' s biological property was tested by barren spot, cross - enutralization and cross - heamagglution inhibited and it was found that it was homological with the standard newcastle disease virus ( ndv ) virulent strain and avirulent strain but it had some diference with the standard strain
本實驗採用spf雞胚及雞胚原代成纖維細胞，從河北省某雞場新城疫免疫抗體很高的病死雞的腦組織中分離得到一株病毒。此株病毒能凝集雞的紅細胞，並且這種凝集可以被特異性抗血清所抑制。 -
Hc ( hog cholera ), the virulent infectious disease caused by hcv ( hog cholera virus ), had been controlled effectively by hclv strain vaccine in the country
豬瘟是由豬瘟病毒引起的豬的一種病毒性傳染病。豬瘟兔化弱毒疫苗有效地控制了豬瘟在我國的急性發生和大流行。 -
Newcastle disease is a highly contagious and economically most important disease of poultry. the disease also inflicts many other avian species. the disease varies in degree of severity ranging from mild, inapparent infecion to severe disease. based on the severity of the disease in chickens, the causative agent of the disease, newcastle disease virus ( ndv ), is divided into three pathotypes : ( 1 ) the lentogenic strains, which cause mild inapparent infection ; ( 2 ) the mesogenic strains, which cause mild respiratory symptoms with low mortality ; ( 3 ) the velogenic strain, which are highly virulent and cause high mortality
新城疫（ newcastledisease ， nd ）是由新城疫病毒（ newcastlediseasevirus ， ndv ）引起的侵害禽類的急性高度接觸性傳染病，是家禽傳染性疾病中危害最嚴害的疫病之一，由於對世界養禽業危害極大，故被國際獸疫局確定為類傳染病。在傳染性疾病的預防中，疫苗是減少易感人群而被最廣泛採用和最有效的途徑。 -
The vaccine was developed by passaging eiav strain liaoning ( eiav l ) in donkeys in vivo, obtaining a donkey - adapted virulent equine infectious anemia virus ( eiav da ) and then passaging it in donkey leukocyte cultures for more than 120 times in vitro
該毒株是將eiavl株（ eiavl ）通過驢體傳代，使其毒力明顯增強，然後在驢白細胞培養物上連續傳代致弱獲得的。 -
The donkey - adapted strain of eiav ( dv116 ), parental strain of eiav - dla, is a highly virulent isolate which was developed by sequential passaging a virulent eiav strain in donkeys in 1970s. the donkeys inoculated with fatal doses of eiav d strain can always be killed within in the first acute disease period. in this study, we constructed a full - length provirus dna clone of dv116 by pcr
本實驗中將eiav驢強毒dv體外感染驢白細胞培養物，一定時間后收獲病毒（本文中簡稱dv116 ） ，提取eiav前病毒dna ，以pcr法分別擴增並克隆了包含全長基因的三段前病毒dna片段，以雙脫氧法測定了dv116病毒全基因序列共8236個核苷酸。 -
The results also indicated that the virulence of the most ibdv field collected in recent years was between the typical very virulent and standard virulent strains. a very virulent strain gx8 / 99 of ibdv was studied for its mortality in spf chickens and commercial egg - type chickens at different age inoculated with bursal suspension of 20 - 2000 eld50 in repeated experiments
選擇致病性最強的來自廣西的gx8 99株，在對法氏囊懸液中病毒用雞胚半數致死量（ eld _ （ 50 ） ）定量測定后，在不同年齡的spf雞和商品代蛋用型塢多次重復地比較研究了該毒株的致病性。 -
This strain ' s virulence was judged by mean death time of chick embryos ( mdt ), intracerebral pathogenicity index in day - old chicks ( icpi ) and intravenous pathogenicity index in 6 - week - old chickens ( ivpi ) and it was found to be the virulent strain. at last, it was tested by the recurrent infection and found that it was the newcastle disease virus ( ndv ), and it was named hbg - 1 strain. in order to find the difference of the cleavage site of this strain with f48e9 and ? 30 strain, a part of the cleavage site of fusion protein gene fragment was amplified by rt - pcr using a primer and sequenced. the sequence analysis showed this strain had low homology with f4ge9 and cso. a phylogenetic tree based on the published sequences of ndv reference strains was constructed and showed the isolated strain hbg - 1 belonged to the genotype w ndv, a novel genotype ndv
為了進一步探尋分離株與標準株的異同，又採用rt - pcr方法，擴增獲得分離株f _ o裂解位點附近的基因片段，經測序后與國際上已發表的新城疫病毒的核酸序列進行比較，結果表明其與標準株和疫苗株之間的同源性較低，僅為82 86之間。經系統發育進化樹分析后，判定該分離株為新城疫病毒（ ndv ）基因型。運用計算機軟體對其裂解位點處的氨基酸序列進行預測和分析，結果表明該分離株為新城疫病毒強毒株並具有基因型的典型結構特徵。 -
The comparison of meq gene sequences of different pathotypes of marek ' s disease virus meq genes of different pathotypes of marek ' s disease virus ( mdv ) were amplified, in the whole opening reading frame ( orf ) by polymerase chain reaction ( pcr ) technique, sequenced and compared with the published sequence of ga strain ( representing vmdv ). cvi988 / rispens and 814, commercial vaccine strains popularly used worldwide and in china respectively ; 648a, representing very virulent plus ( vv + mdv ) and 6 field isolates, originated from guangxi commercial chickens with visceral lymphomas and vaccine breaks, representing high pathogenic ( hpmdv ) and two of them ( g2 and n ) were proved to be vvmdv, were used
本研究通過三個方面進行了研究，取得了如下主要實驗結果： 1mdv不同致病型（ pathotypes ）毒株meq基因序列的比較研究應用pcr技術擴增了不同致病型mdvs ，即國際通用型疫苗毒cv1988 rispens株和中國特有的疫苗毒814株、特超強毒648a株（ vv + mdv ）以及6個廣西分離到的野毒株共9個毒株的meq基因，進行核苷酸序列的測定並與標準強毒ga株（ vmdv ）進行核苷酸和氨基酸序列的比較。 -
The comparative analysis of sequences indicated that the sequences of meq in different pathotypes are relatively conserved and the homology of the amino acid sequences is very high. the significant differences include two mutations in both mdv - 1 vaccine strains cvi988 / rispens and 814 strain : the deletion of a proline ( no. l93aa ), and this mutation is just exactly located in a 15 - amino - acid ( eelcaqlcstppppi ) repeat sequence within the c - terminal transactivation domain of meq protein ; and a point mutation with a shift from alanine ( a ) of all virulent strains to serine ( s ) was occurred on the no. 71 aa
結果發現， mdv不同致病型的meq基因序列相對比較保守，它們相互間核苷酸和氨基酸序列的同源性均很高；但是，與所有七個致瘤性的mdv毒株相比，二個型弱毒疫苗cv1988 rispens株和814株均出現了兩個特徵性的突變：即第194位的p缺失性突變和第71位氨基酸由a變成了s的位點突變；缺失性突變恰恰位於meq基因中轉錄激活域內的一個多脯氨酸的重復序列（ pppp ）之中。 -
The gene was 1668bp in length, encoding the f protein composed of 553 amino acids. sequence analysis and its secondary structure prediction showed that the f protein had three major hydrophobic regions consisting of about 25 amino acids, six potential glycosylation sites and thirteen cysteines. a sequence region of basic amino acids, rrqrrf, was found at the f, - f2 cleavage site, indicating that f4ge9 was a typical virulent strain
序列分析和二級結構預測表明， f _ （ 48 ） e _ （ 9 ）株f蛋白含有3個分別由25個氨基酸組成的疏水區，存在6個潛在的糖基化位點， 13個半胱氨酸殘基，裂解位點區域的氨基酸序列為rrqrrf ，說明f _ （ 48 ） e _ 9株是一株典型的強毒株。 -
Two amino acid substitutions near the vp2 - vp4 cleavage site were identified in the virulent strain jz2000 and might be involved in increased virulence of the virus. phylogenetic analyses indicated that these two strains were most closely related to some european strains but distinct from wibdv and variant strains
分子系統進化樹分析表明， zj2000株和jd1株與cu - 1 、 p2 、 cef94 、 harbin等毒株的關系最近，而與歐洲、香港、日本的超強毒株和美國的變異株相對較遠。 -
The phylogenetic tree was constructed based on sequence comparison and analysis. the result showed that c strain derived from rabbit spleen tissue, c strain adapted to sk6 cell, shimen virulent strain all belonged to group 1. 1, and the prevalent virulent strains belonged to subgroup 2. 1 or subgroup 2. 2. this indicated there were at least two subgroups, which were prevailing in china, and the prevalent virulent strains were diverse far from c. strain vaccine virus
通過序列比較和系統發生關系分析發現： c -株兔組織毒、 c ?株細胞毒和中國50 60年代流行的石門強毒株同屬于組群1 （ group1 ） ；近期豬瘟流行毒株均屬于組群2 （ group2 ）的兩個不同的亞組群（ subgroup2 . 1和2 . 2 ） ，表明我國目前流行毒株至少有2個亞組群。 -
These results showed that the three isolates were infectious bursal disease virus. the full - length cdna of the genomic segment a of two viruses, one virulent field strain ibdv zj2000 and one attenuated strains ibdv jd1, were amplified in a single step procedure by long - accurate reverse - transcription polymerase chain reaction ( la - pcr ), cloned into pgem - t easy vector, and sequenced
分別以傳染性法氏囊病病毒zj2000株（野毒株）和jd1株（弱毒株）基因組dsrna為模板，採用long - accuratert - pcr （ la - pcr ）一步法擴增並克隆了兩株病毒的基因組a節段全長cdna 。 -
Construction of infectious clones of very virulent gx strain of infectious bursal disease virus
株感染性分子克隆的構建 -
There were little difference in the amino acid composition of antigen domain of a, b and c between c strain from rabbit spleen tissue and virulent strains above. this indicated that the prevalence of csf and immunal failure may be not caused by the antigen variation of c stain vaccine virus. the e2 genes of 51 csfv prevalent virulent strains isolated from 12 provinces in china were amplified and sequencd
對c -株兔脾毒與c -株細胞毒、經典強毒e2上的a 、 b 、 c三個中和性抗原區的氨基酸組成進行了比較，其結果為： c -株兔脾毒與c -株疫苗細胞毒的差異很小甚至沒有差異。 -
This result indicated that the virus pd70344v derived from the infectious molecular clone is a highly virulent strain which had inherited main characters from its parental virus dv
這一結果說明本文所構建的感染性分子克隆株pd70344v具有其親本dv株的基本生物學性狀，是一株具有高致病力的衍生病毒。 -
Health experts are worried that a new, more virulent strain may be to blame
衛生專家考慮這歸咎於一種毒力更強的新菌種。 -
Deaths could be dramatically higher if the next pandemic virus is a very virulent strain
若病毒毒性較強，死亡的人數更可能大幅上升。
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