Oral vaccination of pigs with an invasive gyrA-cpxA-rpoB Salmonella Typhimurium mutant.
The potency to protect pigs against colonization and against clinical salmonellosis was evaluated after oral immunization with a live gyrA-cpxA-rpoB Salmonella (S.) Typhimurium mutant (S. Tm. Nal2/Rif9/Rtt). Twenty 4-week-old male hybrid piglets were immunized orally, a control group received a placebo. Three weeks postimmunization, all pigs were challenged orally with a highly virulent S. Typhimurium DT104 strain. Clinical investigation revealed that immunization prevented the vaccinated pigs from clinical symptoms of salmonellosis. While all placebo-treated animals showed a 2-4-day episode of moderate to severe clinical symptoms, 90% of immunized pigs did not show any clinical signs at all. The bacteriological results showed a marked beneficial effect of the oral immunization. Vaccinated pigs showed a significantly decreased rate of colonization of the inner organs (42.5% versus 87.5%) when compared to the placebo-treated animals. Furthermore, in comparison to the non-immunized pigs, the vaccines developed a higher specific immunoglobulin (Ig)A antibody activity, but a significant lower IgM antibody activity in serum. The findings underline the ability of an attenuated oral live S. Typhimurium mutant to prevent clinical symptoms of salmonellosis in pigs and to significantly reduce the colonization of tissues and inner organs, as well as the shedding of S. Typhimurium.
Roesler
Uwe
U
Faculty of Veterinary Medicine, Institute of Animal Hygiene and Veterinary Public Health, University of Leipzig, D-04103 Leipzig, Germany. roesler@vmf.uni-leipzig.de
Marg
Heike
H
Schröder
Ilka
I
Mauer
Stephanie
S
Arnold
Thorsten
T
Lehmann
Jörg
J
Truyen
Uwe
U
Hensel
Andreas
A
D000284:Administration, Oral; D000825:Animal Structures / Q000382:microbiology; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D001426:Bacterial Proteins / Q000235:genetics*; D001428:Bacterial Vaccines / Q000008:administration & dosage* / Q000235:genetics; D015169:Colony Count, Microbial; D027081:DNA Gyrase / Q000235:genetics; D012321:DNA-Directed RNA Polymerases / Q000235:genetics; D004797:Enzyme-Linked Immunosorbent Assay; D005243:Feces / Q000382:microbiology; D008297:Male; D009154:Mutation; D010919:Placebos; D011494:Protein Kinases / Q000235:genetics; D012481:Salmonella Infections, Animal / Q000517:prevention & control*; D012486:Salmonella typhimurium / Q000235:genetics* / Q000254:growth & development / Q000276:immunology; D013552:Swine; D013553:Swine Diseases / Q000517:prevention & control*
D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D001428:Bacterial Vaccines; D010919:Placebos; D011494:Protein Kinases; C092472:CpxA protein, bacteria; D012321:DNA-Directed RNA Polymerases; C105078:RNA polymerase beta subunit; D027081:DNA Gyrase