Protection Conferred by a Live Salmonella Enteritidis Vaccine

CHACANA, P. A.; TERZOLO, H. R.

AVIAN DISEASES

Allen Press, Inc.

Lugar: Lwrence, Kansas, USA; Año: 2006 vol. 50 p. 280 - 283

0005-2086

Fowl typhoid is under control in poultry farms of developed countries, but it still endemically subsists in commerciallaying hen farms of some countries. It has been demonstrated that Salmonella live vaccines can elicit cross-immunity against membersof the same Kauffmann–White scheme serogroup. In this work, we explored the protection conferred by TAD Salmonella vac
E,a live Salmonella enterica serovar Enteritidis vaccine, against fowl typhoid. Three groups of laying hens were vaccinated with differentvaccination schedules starting on the first day of life, and afterwards were infected with 2 3 105 CFU of a virulent SalmonellaGallinarum strain, either at wk 28 or wk 52. Mortality, fecal shedding, and organ invasion of Salmonella Gallinarum were assessed. Inthis work we demonstrated that this Salmonella Enteritidis vaccine is able to cross-immunize against Salmonella Gallinarum. At wk28, hens vaccinated with three oral doses or with two oral doses combined with one subcutaneous dose were protected by the vaccine.At wk 52, when hens were infected 36 wk after the final immunization, the vaccine was not able to confer protection. Thus,revaccination every 3 mo would be highly recommended. In countries where Salmonella Gallinarum subsists together withSalmonella Enteritidis, control programs should include vaccination of laying hens using safe attenuated Salmonella strains.