Attenuation and immunogenicity of a Brucella abortus htrA cycL double mutant in cattle.
Vet Microbiol
; 76(1): 81-90, 2000 Sep 15.
Article
in En
| MEDLINE
| ID: mdl-10925044
ABSTRACT
PHE1 is a htrA cycL double gene deletion mutant of virulent Brucella abortus strain 2308 (S2308) which has previously been evaluated in the murine and caprine models of bovine brucellosis. This report describes the results of studies conducted with this mutant in the natural bovine host. Six sexually mature, non-gravid heifers were inoculated via the conjunctival sac with 1 x 10(10) colony forming units (CFU) of either the parental S2308 or the htrA cycL gene deletion mutant, PHE1. At 4, 7 and 11 days post-inoculation, PHE1 was found to colonize the bovine host at lower levels than S2308. In a second experiment, eight heifers in mid-gestation were infected with 1 x 10(7) CFU of either strain via the conjunctival sac. The virulent S2308 caused abortions or weak calves in 4/4 cows, while all four cows infected with PHE1 had healthy calves. Furthermore, PHE1 exhibited decreased resistance to killing by cultured bovine neutrophils and macrophages compared to the parental strain. These studies demonstrate that the B. abortus htrA cycL gene deletion mutant PHE1 is highly attenuated in the bovine host when compared to the virulent parental S2308.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Bacterial Proteins
/
Brucella abortus
/
Brucellosis, Bovine
/
Serine Endopeptidases
/
Periplasmic Proteins
/
Heat-Shock Proteins
/
Membrane Proteins
Limits:
Animals
Language:
En
Journal:
Vet Microbiol
Year:
2000
Document type:
Article
Affiliation country:
Estados Unidos