Research Notes 2010 Poultry Science 89:495–500 doi: 10.3382/ps.2009-00448

ABSTRACT The current studies were undertaken to assess the ability of humoral immune response in breed-ing hens to provide protective maternal antibody in the progeny. A highly purified outer membrane protein, 34 kDa, was isolated from a virulent strain of Salmonella Gallinarum. Cross-reactivity was observed between this protein and Salmonella Typhi porins; thus we consider this outer membrane protein as a Salmonella Gallinarum porin. To evaluate passive immunity against Salmonella Gallinarum, 200 broiler breeder hens were immunized with either 10 μg of Salmonella Gallinarum porins, 30 μg of Salmonella Gallinarum porins, or PBS without porins as a control group. Anti-Salmonella Gallinarum porin antibodies were detected in broiler breeder serum and in fertile eggs (P < 0.05). Consequently, chickens from immunized broiler breeder hens were protected between 53 to 70 % against challenges of 20 to 500 half-maximal lethal dose of Salmonella Gallinarum (P < 0.001) when compared with control hens that were in-jected with PBS. These results suggest that Salmonella Gallinarum porins, as those of other Salmonella species, participate in the induction of the passive protective immunity, and the humoral immune response may be one of the mechanisms involved in the establishment of this protection. Humoral immune response in breeding hens and protective immunity provided by administration of purified Salmonella Gallinarum porin