Brucella abortus S19 ΔvjbR Live Vaccine Candidate Is Safer than S19 and Confers Protection against Wild-Type Challenge in BALB/c Mice When Delivered in a Sustained-Release Vehicle
Brucellosis is an important zoonotic disease of nearly worldwide distribution. Despite the availability of live vaccine strains for bovine (S19, RB51) and small ruminants (Rev-1), these vaccines have several drawbacks, including residual virulence for animals and humans. Safe and efficacious immuniz...
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Published in | Infection and Immunity Vol. 77; no. 2; pp. 877 - 884 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
American Society for Microbiology
01.02.2009
American Society for Microbiology (ASM) |
Subjects | |
Online Access | Get full text |
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Summary: | Brucellosis is an important zoonotic disease of nearly worldwide distribution. Despite the availability of live vaccine strains for bovine (S19, RB51) and small ruminants (Rev-1), these vaccines have several drawbacks, including residual virulence for animals and humans. Safe and efficacious immunization systems are therefore needed to overcome these disadvantages. A vjbR knockout was generated in the S19 vaccine and investigated for its potential use as an improved vaccine candidate. Vaccination with a sustained-release vehicle to enhance vaccination efficacy was evaluated utilizing the live S19 ΔvjbR::Kan in encapsulated alginate microspheres containing a nonimmunogenic eggshell precursor protein of the parasite Fasciola hepatica (vitelline protein B). BALB/c mice were immunized intraperitoneally with either encapsulated or nonencapsulated S19 ΔvjbR::Kan at a dose of 1 x 10⁵ CFU per animal to evaluate immunogenicity, safety, and protective efficacy. Humoral responses postvaccination indicate that the vaccine candidate was able to elicit an anti-Brucella-specific immunoglobulin G response even when the vaccine was administered in an encapsulated format. The safety was revealed by the absence of splenomegaly in mice that were inoculated with the mutant. Finally, a single dose with the encapsulated mutant conferred higher levels of protection compared to the nonencapsulated vaccine. These results suggest that S19 ΔvjbR::Kan is safer than S19, induces protection in mice, and should be considered as a vaccine candidate when administered in a sustained-release manner. |
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Bibliography: | Corresponding author. Mailing address: Texas A&M University, Veterinary Pathobiology, College Station, TX 77845-1114. Phone: (979) 845-3466. Fax: (979) 862-7472. E-mail: aarenas@cvm.tamu.edu Editor: A. J. Bäumler |
ISSN: | 0019-9567 1098-5522 |
DOI: | 10.1128/IAI.01017-08 |