| 摘要 |
The present invention relates to a live vaccine for the vaccination of poultry and mammals against a variety of gram negative pathogens belonging to Enterobacteriaceae, comprising a bacterial deletion mutant derived from a non-pathogenic strain of E. coli; to a process for obtaining bacterial mutant strain for use in a live vaccine according to claim 1, which comprises exposing a non-pathogenic strain of E. coli to a mutation inducing agent and selecting strains devoid of O-antigens, and cultivating same to obtain the bacteria for use in such live vaccine; to the novel mutant strain E. coli LR-2, and to a process for immunizing poultry and mammals against Enterobacteriaceae which comprises applying to the avian or to the mammal an effective dose of such a vaccine by oral route or as aerosol. |
