Cross-protective immunity in calves conferred by a DNA adenine methylase deficient Salmonellaenterica serovar Typhimurium vaccine.
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.
Mohler
Virginia L
VL
University of Sydney, Faculty of Veterinary Science, Camden, NSW 2570, Australia.
Heithoff
Doug M
DM
Mahan
Michael J
MJ
Walker
Keith H
KH
Hornitzky
Michael A
MA
McConnell
Craig S
CS
Shum
Lucy W C
LW
House
John K
JK
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
D022562:Salmonella Vaccines; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific)