title: Cross-protective immunity in calves conferred by a DNA adenine methylase deficient Salmonellaenterica serovar Typhimurium vaccine.
abstract: The global trend towards intensive livestock production is associated with increased fecal oral pathogen transmission resulting in a high prevalence of Salmonella. Since many pathogenic Salmonella serovars are often endemic to livestock production systems, it is desirable to develop a vaccine that is capable of eliciting immunity to more than one serovar. Here we examined whether immunization with a modified live Salmonella enterica serovar Typhimurium vaccine strain lacking the DNA adenine methylase (Dam) conferred protection in calves against a heterologous S. enterica Dublin challenge. Vaccinated animals challenged with a virulent Dublin strain exhibited a significant attenuation of clinical disease (improved attitude scores and reduced fever and diarrhea) and a concomitant reduction in Dublin fecal shedding and colonization of mesenteric lymph nodes (MLN) compared to non-vaccinated control animals. These data suggest that vaccination with a dam(-) Typhimurium vaccine strain conferred significant cross-protection against clinical disease in cattle attributable to heterologous challenge with Dublin.
authors.affiliation: University of Sydney, Faculty of Veterinary Science, Camden, NSW 2570, Australia.
authors.forename: Virginia L
authors.initials: VL
authors.lastname: Mohler
authors.forename: Doug M
authors.initials: DM
authors.lastname: Heithoff
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Mahan
authors.forename: Keith H
authors.initials: KH
authors.lastname: Walker
authors.forename: Michael A
authors.initials: MA
authors.lastname: Hornitzky
authors.forename: Craig S
authors.initials: CS
authors.lastname: McConnell
authors.forename: Lucy W C
authors.initials: LW
authors.lastname: Shum
authors.forename: John K
authors.initials: JK
authors.lastname: House
mesh_terms: D000818:Animals; D002417:Cattle; D003967:Diarrhea; D005243:Feces / Q000382:microbiology; D005334:Fever; D017353:Gene Deletion; D008198:Lymph Nodes / Q000382:microbiology; D012481:Salmonella Infections, Animal / Q000276:immunology* / Q000382:microbiology / Q000503:physiopathology; D022562:Salmonella Vaccines / Q000235:genetics / Q000276:immunology*; D012486:Salmonella typhimurium / Q000145:classification / Q000201:enzymology / Q000235:genetics / Q000276:immunology*; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific) / Q000235:genetics*; D013045:Species Specificity
chemical_list: D022562:Salmonella Vaccines; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific)