A proteomic approach to the development of DIVA ELISA distinguishing pigs infected with Salmonella Typhimurium and pigs vaccinated with a Salmonella Typhimurium-based inactivated vaccine.
BACKGROUND
Salmonella enterica serovar Typhimurium is one of the most common enteropathogenic bacteria found in pigs in Europe. In our previous work, we demonstrated the protective effects in suckling piglets when their dams had been vaccinated with an S. Typhimurium-based inactivated vaccine. This study is focused on a procedure leading to serological discrimination between vaccinated and infected pigs. As we supposed, distinct environment during natural infection and in bacterial cultures used for vaccine preparation led to a slightly different spectrum of expressed S. Typhimurium proteins. The examination of porcine antibodies produced after the experimental infection with S. Typhimurium or after vaccination with S. Typhimurium-based inactivated vaccine by affinity chromatography and mass spectrometry revealed differences in antibody response applicable for serological differentiation of infected from vaccinated animals.


RESULTS
Antibodies against Salmonella SipB, SipD and SseB proteins were detected at much higher levels in post-infection sera in comparison with control and post-vaccination sera. On the other hand, proteins BamB, OppA and a fragment of FliC interacted with antibodies from post-vaccination sera with a much higher intensity than from control and post-infection sera. In addition, we constructed ELISA assays using post-infection antigen - SipB protein and post-vaccination antigen - FliC-fragment and evaluated them on a panel of individual porcine sera.


CONCLUSIONS
The analysis of antibody response of infected and vaccinated pigs by proteomic tools enabled to identify S. Typhimurium antigens useful for distinguishing infected from vaccinated animals. This approach can be utilized in other challenges where DIVA vaccine and a subsequent serological assay are required, especially when genetic modification of a vaccine strain is not desirable.
Department of Immunology, Veterinary Research Institute, Hudcova296/70, 62100, Brno, Czech Republic. gebauer@vri.cz.|Department of Experimental Biology, Faculty of Science, Masaryk University, Kotlarska267/2, 611 37, Brno, Czech Republic. gebauer@vri.cz.
Jan
J
Gebauer
Department of Immunology, Veterinary Research Institute, Hudcova296/70, 62100, Brno, Czech Republic.
Hana
H
Kudlackova
Bioveta a. s., Komenskeho212/12, 683 23, Ivanovice na Hane, Czech Republic.
Marcel
M
Kosina
Department of Virology, Veterinary Research Institute, Hudcova296/70, 62100, Brno, Czech Republic.
Kamil
K
Kovarcik
Department of Immunology, Veterinary Research Institute, Hudcova296/70, 62100, Brno, Czech Republic.
Radek
R
Tesarik
Department of Immunology, Veterinary Research Institute, Hudcova296/70, 62100, Brno, Czech Republic.|Faculty of Veterinary Medicine, University of Veterinary and Pharmaceutical Sciences, Palackeho 1/3, 612 42, Brno, Czech Republic.
Alena
A
Osvaldova
Department of Immunology, Veterinary Research Institute, Hudcova296/70, 62100, Brno, Czech Republic.
Martin
M
Faldyna
Department of Immunology, Veterinary Research Institute, Hudcova296/70, 62100, Brno, Czech Republic.
Jan
J
Matiasovic
D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D000942:Antigens, Bacterial / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary*; D040901:Proteomics; D012481:Salmonella Infections, Animal / Q000175:diagnosis* / Q000276:immunology; D022562:Salmonella Vaccines / Q000276:immunology*; D012486:Salmonella typhimurium / Q000235:genetics; D013552:Swine; D013553:Swine Diseases / Q000175:diagnosis* / Q000276:immunology; D015164:Vaccines, Inactivated / Q000276:immunology
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D022562:Salmonella Vaccines; D015164:Vaccines, Inactivated
DIVA vaccine; Mass spectrometry; Porcine; Recombinant protein; Salmonella Typhimurium