Genetically engineered enteropathogenic XXXX elicits a specific immune response and protects against a virulent challenge.

@entity1 @entity851 @entity294 @entity95 @entity526
Enteropathogenic @entity526 (EPEC), a major cause of severe disease with @entity294 in @entity1 , is also involved in weaned @entity95 colibacillosis. EPEC O103 is frequent in @entity95 -fattening units of Western Europe. It causes high mortality and @entity851 , leading to substantial economic losses. We report here the construction by allelic exchange of an EPEC O103 strain mutated in espB and tir, two essential virulence genes. Upon live oral administration to weaned @entity95 , the E22DeltaTir/EspB mutant strain efficiently colonized the intestinal tract without any adverse consequences. The @entity95 were challenged with the highly pathogenic parental strain E22. The mutant provided complete protection to @entity95 and total resistance to intestinal colonization by E22. In addition, E22DeltaTir/EspB strain induced a specific humoral response against the bacterial adhesin AF/R2. These Abs prevent bacterial attachment to epithelial cells in vitro. These results open the way for the development of an efficient vaccine strategy against @entity95 EPEC infections.
