| abstract |
The present invention relates to the field of novel, engineered Gram-negative bacterial strains that have improved outer-membrane vesicle shedding properties, and vaccine compositions comprising these bacteria or vesicles. The present invention provides a hyperbledding Gram-negative bacterium which has been genetically modified by either or both processes selected from a group of consisting of: down-regulation of expression of one or more tol genes; and mutation of one or more gene(s) encoding a protein comprising a peptidoglycan-associated site to attenuate the peptidoglycan-binding activity of the protein(s). |