Libby S J, Goebel W, Ludwig A, Buchmeier N, Bowe F, Fang F C, Guiney D G, Songer J G, Heffron F
Department of Molecular Biology, Research Institute of Scripps Clinic, La Jolla, CA 92037.
Proc Natl Acad Sci U S A. 1994 Jan 18;91(2):489-93. doi: 10.1073/pnas.91.2.489.
A Salmonella gene encoding a cytolysin has been identified by screening for hemolysis on blood agar. DNA sequence analyses together with genetic mapping in Salmonella suggest that it is unrelated to other toxins or hemolysins. The gene (slyA) is present in every strain of Salmonella examined, in Shigella, and in enteroinvasive Escherichia coli but not in other Enterobacteriaceae. SlyA (salmolysin) purified from a derivative of the original clone has hemolytic and cytolytic activity and has a molecular weight predicted by the DNA sequence. The median lethal dose and infection kinetics in mice suggest that the toxin is required for virulence and facilitates Salmonella survival within mouse peritoneal macrophages.
通过在血琼脂平板上筛选溶血现象，已鉴定出一个编码溶细胞素的沙门氏菌基因。沙门氏菌的DNA序列分析及基因定位表明，它与其他毒素或溶血素无关。该基因（slyA）存在于所检测的每一株沙门氏菌、志贺氏菌和肠侵袭性大肠杆菌中，但在其他肠杆菌科细菌中不存在。从原始克隆的衍生物中纯化得到的SlyA（沙门溶血素）具有溶血和溶细胞活性，其分子量与DNA序列预测的一致。小鼠的半数致死剂量和感染动力学表明，该毒素是毒力所必需的，且有助于沙门氏菌在小鼠腹腔巨噬细胞内存活。
