Development of Brucella melitensis Rev.1 ΔOmp19 mutants with DIVA feature and comparison of their efficacy against three commercial vaccines in a mouse model. (May 2021)

• Record Type: Journal Article
• Authors: Uslu, Ali; Erganis, Osman
• Is Part Of: Molecular immunology. Volume 133(2021)
• Page Start: 44
• Page End: 52
• Publication Date: 2021-05
• Subjects: Brucella melitensis Rev.1 -- Suicide plasmid -- Omp19 -- Gene deletion -- Marker vaccine -- Mouse model; Immunochemistry -- Periodicals; Molecular biology -- Periodicals; Immunochemistry -- Periodicals; Allergy and Immunology -- Periodicals; Molecular Biology -- Periodicals; Immunochimie -- Périodiques; Biologie moléculaire -- Périodiques; Immunochemistry; Molecular biology; Periodicals; Electronic journals; 571.96
• DOI: 10.1016/j.molimm.2021.02.006
• Languages: English
• ISSNs: 0161-5890

Abstract

Highlights: B. melitensis Rev.1 has been used uneventfully in sheep–goats since develop. Nevertheless, the vaccine strain does not help distinguish infected animals from vaccinated ones. Omp19 is antigenically one of the proteins that determine the severity of the disease. As transmission model using spheroplast cell enables gene transfer successfully to Brucella, which can select as a mutant strain of vaccination strategies. B. melitensis Rev.1 ΔOmp19 strain can be made differentiation with ELISA (coated with Omp 19 protein) test for screening from vaccinated/infected (DIVA) target animal. Abstract: Brucella is an intracellular zoonotic pathogen that can affect many hosts. Brucella melitensis Rev.1 is a live attenuated, is one of the most effective vaccine strain against brucellosis. It can be used safely in sheep, goats, and even cattle. Although many studies are available on this topic, there is no effective vaccine strain for sheep and goats that distinguishes the antibody titer produced between the field infections and vaccinations. Outer membrane protein 19 (Omp 19) is both virulent and a protective antigen found on the cell-wall of the Brucella strain. In this study, used the suicide plasmid pJQ200KS, which contained homologous region without Omp19 Open Reading Frame (ORF) that was transferred to B. melitensis Rev.1 and further transformed into spheroplasts along with penicillin, ampicillin, and glycine by electroporation. To obtain a mutant vector from Escherichia coli, we used the heat shock transformation method along with the blue-white colony screening using X-gal media, whereas for the gene transfer in Brucella, we used electroporation. A scanning electron microscope (S.E.M) was used to observe the spheroplast transformation while the mutant vector and deletion mutants were confirmed through PCR and sequence analysis. In the mouse model efficacy trials, three commercial vaccines were found to comply with the OIE standards. Although the deletion mutants 19 and 44/10 had similar efficiency as the commercial vaccines in terms of stimulation power, the ELISA test with Omp19 protein showed the same results as the negative control. The Rev.1 Omp19 deletion mutants obtained in this study contained sufficient residual virulence, and their protective immunity was similar to the commercial vaccines. The study showed that a vaccine prepared using a B. melitensis Rev.1 ΔOmp19 can act as a marker vaccine or differentiate infected from vaccinated animals (DIVA) through the ELISA test that detects the Omp19 protein.