摘要 |
The phoP gene and its equivalents are of a type which have ''global regulation of pathogenicity'', i.e., they coordinately regulate a number of genes including those that encode bacterial virulence factors. In Salmonella, the phoP gene product also controls the expression of non-specific acid phosphatase from the phoN gene. A central feature of the invention are microorganisms which are avirulent as a result, in whole or in part, of a mutation in phoP, but which retain their immunogenicity. These cells are suitable as components of live vaccines. |