Franzon V L, Arondel J, Sansonetti P J
Unité de Pathogénie Microbienne Moléculaire, Institut Pasteur, Paris, France.
Infect Immun. 1990 Feb;58(2):529-35. doi: 10.1128/iai.58.2.529-535.1990.
A Shigella flexneri serotype 5 strain deficient in the production of the iron-containing superoxide dismutase FeSOD (sodB) and a catalase-negative (katFG) S. flexneri serotype 5 strain were isolated. Both strains were examined for increased sensitivity to oxygen stress by using assays involving killing by mouse peritoneal macrophages and human polymorphonuclear leukocytes as well as infection of rabbit ileal loops. The sodB mutant was extremely sensitive to killing by phagocytes when compared with the wild-type parent, M90T. The catalase mutant also showed an increased sensitivity to killing, but to a much lesser extent. Upon infection of rabbit ileal loops and subsequent histopathological examination, the sodB mutant caused very little detectable damage to intestinal villi. The pattern of infection was roughly similar to that of BS176, an avirulent plasmidless derivative of M90T. The katFG mutant, on the other hand, showed a high degree of destruction, similar to that caused by M90T. This evidence suggests that the superoxide dismutase encoded by sodB may play an important role in the pathogenesis of S. flexneri. In contrast, catalases appear to make a limited contribution to virulence.
分离出一株弗氏志贺菌5型菌株，该菌株缺乏含铁超氧化物歧化酶FeSOD（sodB）的产生，以及一株过氧化氢酶阴性（katFG）的弗氏志贺菌5型菌株。通过使用涉及小鼠腹腔巨噬细胞和人多形核白细胞杀伤以及兔回肠袢感染的试验，检测了这两种菌株对氧应激的敏感性增加情况。与野生型亲本M90T相比，sodB突变体对吞噬细胞杀伤极为敏感。过氧化氢酶突变体也表现出对杀伤的敏感性增加，但程度要小得多。在感染兔回肠袢并进行后续组织病理学检查时，sodB突变体对肠绒毛造成的可检测损伤非常小。感染模式与M90T的无毒无质粒衍生物BS176大致相似。另一方面，katFG突变体表现出高度的破坏，类似于M90T造成的破坏。这一证据表明，由sodB编码的超氧化物歧化酶可能在弗氏志贺菌的发病机制中起重要作用。相比之下，过氧化氢酶对毒力的贡献似乎有限。
