The present invention relates to a Klebsiella pneumoniae gene-deleted mutant and its producing methods. The main objective of this invention is to construct a Klebsiella pneumoniae tonB deletion mutant used as an immunogenically effective amount of a live attenuated vaccine against the community-acquired pyogenic liver abscess, where the tonB gene was deleted. The tonB deletion mutant maintained the structure of the capsular polysaccharide on cell membrane surface, and induced no disease on the mouse after injection. In addition, the tonB deletion mutants induced the immunity against pyogenic liver abscess caused by Klebsiella pneumoniae. 展开▼
