It indicated that the chinese isolates belong to north american group . two pairs of different primers of orf7 were used to identify the genotype of prrsv isolates in china , and then compared with the reference isolates of north american and european serotype and modified live prrsv vaccine . the results further proved that prrsv prevalent in china belongs to b genetype . combining the restriction enzyme digestion patterns obtained from mini , hindi and sactt , we observed 2 distinct rflp patterns 在此基础上，扩增各毒株的orf5基因，用mlu , hinc和sac限制性内切酶切割orf5基因，通过这3种限制性内切酶获得了各毒株的orf5基因限制性酶切图谱，经rflp分析表明国内分离毒株与美洲型强毒株有着相同的rflp图谱，而与疫苗毒的rflp图谱存在明显差异，进一步证明国内分离毒株的基因型属于美洲型的强毒株。
The result showed that the homology rate of pila gene among the 5 avian pathogenic e . coli strains tested and one human e . coli were from 89 . 8 % to 91 . 1 % , and the homology rate of amino acid were from 88 . 5 % to 91 . 8 % . the homology rate of pila gene sequence among 5 avian pathogenic e . coli strains tested and avian pathogenic e . coli reported ( serotype o1 , o2 , o78 ) were from 87 . 8 % to 90 . 2 % , and the homology rate of amino acid were from 84 . 6 % to 91 . 2 % . there had homology in avian pathogenic e . coli . there had some common antigen side in type 1 pili of avian pathogenic e . coli 结果表明：运用msha法检测1型菌毛的检出率为80 ( 36 45 ) ， pcr法的检出率为95 . 5 ( 43 45 ) ， pcr方法用于1型菌毛的检测比msha更加敏感、快速、特异性强；选择5株优势血清型鸡源致病性大肠杆菌代表株( o _ ( 89 ) ， o _ ( 119 ) ， o _ ( 141 ) ， o _ ( 127 ) )的1型菌毛pila基因的pcr扩增片段经纯化后，分别定向克隆到puc18质粒的多克隆位点，构建了含有目的基因片段的克隆质粒，并转化到dh5株大肠杆菌载体菌中，筛选获得阳性克隆菌株。
The 38mda plasmid containing cryla ( b ) and cryii genes from ybt - 791 was purified and transformed by electroporation into the acrystalliferous mutants 4d10 ( serotype h3ab ) and bti ips 78 / 11 ( serotype h14 ) . the two different serotype transformants , mbl - 1 and mbl - 2 harboring cryl a ( b ) and cryii were obtained , respectively . sds - page analysis showed that the transformants could express 130kda and 65kda proteins 并将携带有cry a ( b )和cry基因的38mda质粒分别电转化到不同血清型苏云金芽胞杆菌无晶体突变株4d10 ( h _ ( 3ab ) )和btiips ? 78 11 ( h _ ( 14 ) )中，证明了相同基因型在不同血清型受体中有不同的杀虫活性。
1 . expression of cry genes located in native plasmid in different flagella serotype strains to study cloning and expression of icps genes , an ecor i - f fragment of cryla ( a ) gene from pesi was inserted into pselect - 1 with t7 rna polymerase promoter in vitro . the plasmids of bacillus thuring fensisybt - 803 and ybt - 791 were analyzed by southern hybridization using an rna probe of ecori - f fragment and by pcr identification with cryl mixture primers 将cry基因的高保守区的cry a ( a ) ecog - f片段插入带有t7rna聚合酶启动子的质粒pselect - 1 ，获得了能在体外转录的rna探针载体pbpl - 1 ，用该载体制备的rna探针具有特异强，背景清楚，省时省力等优点，已成功地用于苏云金芽胞杆菌的分子生物学研究和特异菌株的筛选。
Botulinum neurotoxin serotype a produced by the clostridium botulinum , are the most lethal substances known . a single molicule can abolish the function of a nerve cell . the toxins exert their action by blocking the release of the neurotransmitter , acetylcholie , at the neuromuscular junction , the blockage of bont / a makes neuromuscular weakness and flsccid paralysis , and lead to respiratory failure and death . botulinum is a serious public heath problem in developing countries around the world A型肉毒毒素( botulinumneurotoxinserotypea ， bont a )是由肉毒梭菌产生的一种强烈的外毒素，是目前已知最毒的天然物质，一个单分子的肉毒素分子就能阻断一个神经细胞的功能，通过阻断运动神经末梢乙酰胆碱的释放导致机体发生瘫痪，严重者发生呼吸衰竭而死亡。
Colibacollosis serotype k . 99 positive sera in ducks and duck plague positive sera were tested , whereas , the results of detection to r . a . sera were positive . the sensitivity of indirect elisa were 50 to 100 times ( serotype 1 ) , ( 2 ) 25 to 100 times ( serotype 2 ) , ( 3 ) 12 to 100 times ( serotype 4 ) and 25 to 200 times ( serotype 5 ) th an micro - agglutination test 包被鸭疫里默氏杆菌抗原时，对鸭抗5 ： a多杀性巴氏杆菌阳性血清、鸭抗型鸭病毒性肝炎阳性血清、鸭抗鸭源大肠杆菌k _ ( 88 )阳性血清、鸭抗鸭源肠炎沙门氏菌阳性血清、鸭抗鸭源大肠杆菌k _ ( 99 )阳性血清、鸭抗鸭瘟阳性血清检测结果呈阴性。
