Effect of superoxide dismutase gene inactivation on virulence of Pseudomonas aeruginosa PAO1 toward the silkworm, Bombyx mori
Effect of superoxide dismutase gene inactivation on virulence of Pseudomonas aeruginosa PAO1 toward the silkworm, Bombyx mori
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DOI：
10.1128/aem.00981-06
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发表时间：
2007-03-01
影响因子：
4.4
通讯作者：
Shimizu, Susumu
中科院分区：
文献类型：
--
作者：
Iiyama, Kazuhiro;Chieda, Yuuka;Shimizu, Susumu
为了研究超氧化物歧化酶（SOD）在家蚕（Bombyx mori）毒力中的作用，我们制备了铜绿假单胞菌（Pseudomonas aeruginosa）缺乏锰-SOD （PAO1sodM）、铁-SOD （PAO1sodB）或两者兼有（PAO1sodMB）的突变体。将突变体注射到家蚕的血液中。毒力大小顺序为PAO1 = PAO1sodM > PAO1sodB > PAO1sodMB。特别是，PAO1sodMB在10(5)个细胞或更少的剂量下是无毒的。然后将sod双突变体PAO1sodMB与pSodM或pSodB进行反式互补。在两种补充菌株中，毒力都部分恢复。在这两个质粒中，pSodB对P. aeruginosa对B. mori的毒力贡献更大。在家蚕血淋巴肉汤中的生长结果和显微分析表明，sod突变体的迟滞期和超氧化物敏感性与毒力下降有关。综上所述，铜绿假单胞菌（P. aeruginosa）对B. mori的完全毒力需要sod， Fe-SOD在感染过程中比Mn-SOD更重要。
To investigate the role of superoxide dismutase (SOD) in virulence against the silkworm, Bombyx mori, mutants of Pseudomonas aeruginosa PAO1 lacking manganese-SOD (PAO1sodM), iron-SOD (PAO1sodB), or both (PAO1sodMB) were generated. The mutants were injected into the hemocoel of B. mori. The virulence decreased in the order PAO1 = PAO1sodM > PAO1sodB > PAO1sodMB. In particular, PAO1sodMB was avirulent at a dose of 10(5) cells or less. The sod double mutant PAO1sodMB was then complemented with either pSodM or pSodB in trans. In both the complemented strains, the virulence was partially restored. Of the two plasmids, pSodB contributed more to the virulence of P. aeruginosa against B. mori. The results of growth in B. mori hemolymph broth and microscopic analysis suggested that a longer lag phase and superoxide sensitivity correlated with decreased virulence in sod mutants. In conclusion, the SODs are required for full virulence of P. aeruginosa against B. mori and Fe-SOD is more important than Mn-SOD in the infection process.