DISSEMINATION OF BACTERIAL ENTEROTOXIN GENES

我们从猪的体内克隆了耐热肠毒素STII基因。 并测定了其DNA序列。初步数据 这表明人类分离的大肠杆菌、沙门氏菌和志贺氏菌也 含有这种STII基因。大肠杆菌中的STII基因位于两个 反向重复序列，表明它与一种 转座因子。STII基因的转座能力将是 确定并检查插入部位的性质。这个 STII转座子的大小和转座所必需的序列 将会被确定。由于接壤的末端反向重复区域 STII基因很大，这些区域可能是， 转座子本身，将被调查。的可移位性 在其他大肠杆菌分离株中的STII基因将被检测。如果换位 发生，则可转置元素的结构将是 下定决心。最后，我们将启动类似的研究，以确定 其他产肠毒素菌中STII基因的存在及结构分析 细菌。然后对存在于其他细菌中的STII基因进行检测 为了可转位。以这种方式，关于分子的信息 大肠埃希菌的性质、传播机制和分布 将获得细菌间的STII基因。

We have cloned the gene for the heat-stable enterotoxin STII from a porcine strain of E. coli and determined its DNA sequence. Preliminary data suggest that human isolates of E. coli, Salmonella, and Shigella also contain this STII gene. The STII gene in E. coli is located between two inverted repeat sequences, suggesting that it is associated with a transposable element. The transposability of the STII gene willl be determined and the nature of the insertion sites will be examined. The size of the STII transposon and the sequences essential for transposition will be ascertained. Since the terminal inverted repeat regions bordering the STII gene are large, the possibility that these regions are, themselves, transposons will be investigated. The transposability of the STII gene in other E. coli isolates will be examined. If transposition occurs, then the structure of the transposable elements will be determined. Finally, we will initiate similar studies to determine the presence and structure of STII gene in other species of enterotoxigenic bacteria. The STII genes present in other bacteria will then be assayed for transposability. In this manner, information concerning the molecular nature, the mechanism of dissemination, and the distribution of the E. coli STII gene among bacterial will be obtained.