鸭疫里氏杆菌江苏分离株G＋C含量测定及DNA同源性研究

采用苯酚－氯仿混合法，提取了鸭疫里氏杆菌（Ｒｉｅｍｅｒｅｌｌａ ａｎａｔｉｐｅｓｔｉｆｅｒ）血清１型Ｊｂ２株，Ｊｂ３株，未定型菌Ｔｂ１株以及鸭大肠杆菌Ｅ４株和大肠杆菌Ｋ１２株的基因组ＤＮＡ。用热变性法测得Ｊｂ２，Ｊｂ３，Ｔｂ１和Ｋ１２株的解链温度分别为６８．５，６８．５，６９．０和７３．５℃（缓冲液为０．１×ＳＳＣ）。由计算可知Ｊｂ２，Ｊｂ２和Ｔｂ１株的Ｇ＋Ｃ含量分别为３５．６２％，３５．６２％和

DNA base composition and homology values in the isolates of Riemerella anatipestifer

DNAs were extracted from R. anatipestifer strain Jb 2, Jb 3, E. coli strain E 4 (from duck) and K 12 , and unidentified strain Tb 1 by phenol and chloroform extract method. The guanine plus cytocine (G+C) contents of them were determined by thermal denaturation temperature method. The result showed that (G+C)% of the Jb 2, Jb 3 and Tb 1 strains was 35.62%, 35.62% and 36.67% respectively. The DNAs homology for Jb 2 and Jb 3 strains, Jb 2 and Tb 1 strains, Jb 2 and E 4 strains were carried out by liquid phase reassociation rate method. The result showed that DNAs from Jb 2 strain shared 68.63% and 68.94% homology with that from Jb 3 and Tb 1 strain respectively, while the homology of E 4 strain to Jb 2 strain was 0%.