Identification of Legionella pneumophila genes important for infection of amoebas by signature-tagged mutagenesis.
Identification of Legionella pneumophila genes important for infection of amoebas by signature-tagged mutagenesis.
复制标题
通过特征标记诱变鉴定对阿米巴感染重要的嗜肺军团菌基因。
DOI：
10.1128/iai.69.2.977-987.2001
复制
发表时间：
2001
影响因子：
3.1
通讯作者：
Tompkins,LS
中科院分区：
文献类型：
--
作者：
Polesky,AH;Ross,JT;Falkow,S;Tompkins,LS
嗜肺军团菌是一种引起人类肺炎的兼性细胞内革兰氏阴性杆菌。自由生活的变形虫被认为是军团菌感染的宿主。签名标记的诱变被用来鉴定嗜肺军团菌在卡氏阿米巴中生存所必需的。6株突变株在侵袭和细胞内生长试验中有缺陷。四个突变体也表现出入侵和复制缺陷，在蠕虫状哈特曼氏菌，一种阿米巴与医院暴发的军团菌。还在来源于外周血单核细胞的巨噬细胞中测试了六种突变体。两个突变体有细胞内复制缺陷，两种不同的菌株进入细胞的效率较低。在已知的L中有两个转座子插入。pneumophilagenes，lspKandaroB.另外四个是新基因。一个基因与荧光假单胞菌的细胞色素型生物合成蛋白相似。另一个与霍乱弧菌中调节鞭毛生物合成的转录激活因子相似。第三类与根瘤菌属（Rhizobiumsp.）菌株NGR 234，其参与DNA的接合转移。第四个没有同源性。通过使用生存在变形虫作为选择，我们已经分离出具有一系列表型的突变株，我们已经潜在地确定了新的L。嗜肺毒力基因
Legionella pneumophilais a facultative intracellular gram-negative rod that causes pneumonia in humans. Free-living amoebas are thought to serve as a reservoir forLegionellainfections. Signature-tagged mutagenesis was employed to identifyLegionella pneumophilagenes necessary for survival in the amoebaAcanthamoeba castellanii. Six mutant strains were defective in assays of invasion and intracellular growth. Four mutants also exhibited invasion and replication defects inHartmannella vermiformis, an amoeba linked to hospital outbreaks ofLegionellapneumonia. The six mutants also were tested in macrophages derived from peripheral blood mononuclear cells. Two mutants had intracellular replication defects, and two different strains entered cells less efficiently. Two transposon insertions were in knownL. pneumophilagenes,lspKandaroB. The other four were in novel genes. One gene has similarity to a cytochromec-type biogenesis protein ofPseudomonas fluorescens. Another has similarity to a transcriptional activator regulating flagellar biosynthesis inVibrio cholera. The third is similar totraAofRhizobiumsp. strain NGR234, which is involved in conjugal transfer of DNA. The fourth has no homology. By using survival in amoeba as a selection, we have isolated mutant strains with a range of phenotypes; and we have potentially identified newL. pneumophilavirulence genes.