title: Evaluation of protective efficacy of live attenuated Salmonella enterica serovar Gallinarum vaccine strains against fowl typhoid in chickens.
abstract: Salmonella enterica serovar Gallinarum is the etiological agent of fowl typhoid, which constitutes a considerable economic problem for poultry growers in developing countries. The vaccination of chickens seems to be the most effective strategy to control the disease in those areas. We constructed S. Gallinarum strains with a deletion of the global regulatory gene fur and evaluated their virulence and protective efficacy in Rhode Island Red chicks and Brown Leghorn layers. The fur deletion mutant was avirulent and, when delivered orally to chicks, elicited excellent protection against lethal S. Gallinarum challenge. It was not as effective when given orally to older birds, although it was highly immunogenic when delivered by intramuscular injection. We also examined the effect of a pmi mutant and a combination of fur deletions with mutations in the pmi and rfaH genes, which affect O-antigen synthesis, and ansB, whose product inhibits host T-cell responses. The S. Gallinarum Δpmi mutant was only partially attenuated, and the ΔansB mutant was fully virulent. The Δfur Δpmi and Δfur ΔansB double mutants were attenuated but not protective when delivered orally to the chicks. However, a Δpmi Δfur strain was highly immunogenic when administered intramuscularly. All together, our results show that the fur gene is essential for the virulence of S. Gallinarum, and the fur mutant is effective as a live recombinant vaccine against fowl typhoid.
authors.affiliation: The Biodesign Institute, Arizona State University, Tempe, Arizona, USA.
authors.forename: Paweł
authors.initials: P
authors.lastname: Laniewski
authors.affiliation: The Biodesign Institute, Arizona State University, Tempe, Arizona, USA.
authors.forename: Arindam
authors.initials: A
authors.lastname: Mitra
authors.affiliation: Global Biological Research and Development, Zoetis Animal Health, Kalamazoo, Michigan, USA.
authors.forename: Kemal
authors.initials: K
authors.lastname: Karaca
authors.affiliation: Global Biological Research and Development, Zoetis Animal Health, Kalamazoo, Michigan, USA.
authors.forename: Ayub
authors.initials: A
authors.lastname: Khan
authors.affiliation: Global Biological Research and Development, Zoetis Animal Health, Kalamazoo, Michigan, USA.
authors.forename: Rajeev
authors.initials: R
authors.lastname: Prasad
authors.affiliation: The Biodesign Institute, Arizona State University, Tempe, Arizona, USA School of Life Sciences, Arizona State University, Tempe, Arizona, USA.
authors.forename: Roy
authors.initials: R
authors.lastname: Curtiss
authors.affiliation: The Biodesign Institute, Arizona State University, Tempe, Arizona, USA kenneth.roland@asu.edu.
authors.forename: Kenneth L
authors.initials: KL
authors.lastname: Roland
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics; D002645:Chickens; D017353:Gene Deletion; D007273:Injections, Intramuscular; D011201:Poultry Diseases / Q000276:immunology / Q000517:prevention & control*; D012097:Repressor Proteins / Q000235:genetics; D012481:Salmonella Infections, Animal / Q000276:immunology / Q000517:prevention & control*; D022562:Salmonella Vaccines / Q000008:administration & dosage / Q000276:immunology* / Q000302:isolation & purification; D019779:Salmonella enterica / Q000235:genetics / Q000276:immunology*; D016019:Survival Analysis; D016896:Treatment Outcome; D014613:Vaccines, Attenuated / Q000008:administration & dosage / Q000276:immunology / Q000302:isolation & purification; D014774:Virulence
chemical_list: D001426:Bacterial Proteins; D012097:Repressor Proteins; D022562:Salmonella Vaccines; D014613:Vaccines, Attenuated; C068477:ferric uptake regulating proteins, bacterial