Bacteria attenuated by a non-reverting mutation in each of the aroc, ompf and ompc genes, useful as vaccines

摘要

The invention provides a bacterium attenuated by a non-reverting mutation in each of the aroC gene, the ompF gene and the ompC gene. The bacterium is useful as a vaccine. The bacterium may, for example, be an attenuated strain of E. coli useful in vaccination against diarrhoea.