Open AccessInactivation of pyocyanin synthesis genes has no effect on the virulence of Pseudomonas aeruginosa PAO1 toward the silkworm, Bombyx mori
Author(s) -
Chieda Yuuka,
Iiyama Kazuhiro,
Lee Jae Man,
Kusakabe Takahiro,
YasunagaAoki Chisa,
Shimizu Susumu
Publication year - 2008
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.2007.00982.x
Subject(s) - pyocyanin , pseudomonas aeruginosa , bombyx mori , virulence , microbiology and biotechnology , gene , pseudomonadales , pseudomonadaceae , chemistry , biology , bacteria , biochemistry , genetics , quorum sensing
The contribution of pyocyanin to the virulence of Pseudomonas aeruginosa against the silkworm Bombyx mori was studied. First, purified pyocyanin was injected into the hemocoel of B. mori . Acute toxicity was observed only when a high dose of pyocyanin was injected. The lethal dose 50% value of pyocyanin was found to be 9.52 μg per larva. Next, mutant strains of phzM and phzS , which encode putative phenazine‐specific methytransferase and flavin‐containing monooxygenase, respectively, were created, and their virulence was compared with that of the PAO1 parent strain. Although the ability to produce pyocyanin was completely lost in the phz ‐mutant strains, they maintained the same level of virulence as the PAO1 parent strain. In addition, the complementation of the corresponding gene in trans in the mutant strains did not have any effect on the virulence of those mutant strains. These results indicated that pyocyanin does not act as a virulence factor in B. mori after invasion, which was different from the results obtained in other Lepidopteran host models.