1. Mycobacterium bovis mutant in the virulence factors PhoP, ESAT-6 and CFP-10 persisted in mouse organs after a year post-vaccination.
- Author
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Blanco FC, Vázquez CL, García EA, Rocha RV, Klepp LI, and Bigi F
- Subjects
- Animals, Bacterial Load, Female, Disease Models, Animal, Time Factors, Vaccination, Tuberculosis Vaccines immunology, BCG Vaccine immunology, Virulence, Mice, Mice, Inbred BALB C, Mycobacterium bovis pathogenicity, Mycobacterium bovis genetics, Mycobacterium bovis immunology, Bacterial Proteins genetics, Bacterial Proteins immunology, Lung microbiology, Lung immunology, Mutation, Virulence Factors genetics, Antigens, Bacterial immunology, Antigens, Bacterial genetics, Spleen microbiology, Spleen immunology
- Abstract
A vaccine for bovine tuberculosis is urgently needed. The BCG vaccine (the Bacille Calmette-Guérin), currently the only licensed vaccine for tuberculosis in humans, offers variable protection in cattle. However, BCG is a highly safe vaccine, and any alternative vaccine must not only offer greater protection than BCG but also match and improve its safety profile. Mice are the most widely used animal models in tuberculosis research, particularly for pre-clinical vaccine evaluation. In these animal models, the key indicator of infection or vaccine efficacy is the mycobacteria load in the lungs. In this study, we evaluated the long-term protection conferred by vaccinating BALB/c mice with a Mycobacterium bovis triple mutant lacking the virulence genes phoP, esxA, and esxB. Our findings showed that the triple mutant protected the lungs of mice against M. bovis challenge for up to one-year post-vaccination. However, the bacterial load in the spleens predominantly comprised the vaccine strain, and the lungs also contained some of these bacteria. These results suggest that the vaccine strain persisted in the mouse organs for at least one year, which raised concerns about its potential safety for animal vaccination., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)
- Published
- 2024
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