The eha mutant were attenuated by LD50.

The bacterial loads of the mutant displayed a different profile from the one of the wild strain.

The tissues infected with the wild strains showed the most extensive inflammation, but the mutant infection was a lack of the histopathological alterations.

The eha gene can activate directly eseC, fliC and pagC.

The wild strain was more toxic to macrophages, and induced less the host apoptotic responses than the mutant did.