ABSTRACT
Brucellosis is an infectious disease affecting humans and animals worldwide. Effective methods of control include inducing immunity in animals by vaccination and elimination. Brucella abortus S19 is one of the popular vaccines for control of cattle brucellosis, as it has low virulence. In this paper, allelic exchange plasmids of wzm and wzt genes were constructed and partially knocked out to evaluate the effects on the induction of immunity to Brucella abortus S19 mutants. Cytokine secretion in vitro, INF-γ induction in vivo and antibody dynamics were evaluated. These data suggested that the immunity-eliciting ability of the wzm and wzt gene deletion mutants was similar, although reduced compared with the S19 strain. The results demonstrated that the wzt gene may be more important in the regulation of the induction of immunity than the wzm gene.
Subject(s)
ATP-Binding Cassette Transporters/genetics , Bacterial Proteins/genetics , Brucella abortus/pathogenicity , Brucellosis/immunology , ATP-Binding Cassette Transporters/immunology , Animals , Bacterial Proteins/immunology , Brucella Vaccine , Brucella abortus/immunology , Brucellosis/pathology , Brucellosis/prevention & control , Cattle , Humans , Sequence Deletion , VirulenceABSTRACT
The molecular tag vaccine against Brucella abortus and serological testing are the main methods of prevention of brucellosis used currently. They can discriminate vaccinated animals and humans from those naturally infected. In this study, we constructed a gene deletion mutant strain, B. abortus S19 virB5 with a molecular tag. Recombinant VirB5 was expressed and purified for evaluation as a diagnostic reagent for bovine brucellosis. In total, 400 sera samples were tested using a VirB5 antigen-based enzyme-linked immunosorbent assay (ELISA) and the results were compared with those of the standard tube agglutination test (SAT). This showed that the sensitivity was 88.2%, specificity was 97.8% and accuracy was 94.8%. Recombinant VirB5 could also be used to discriminate B. abortus-infected mice from mice infected with the B. abortus S19 virB5 mutant strain. It was concluded that recombinant VirB5 could be used as a potential antigen and serological marker for the diagnosis of bovine brucellosis.
Subject(s)
Antibodies, Bacterial/blood , Bacterial Proteins/immunology , Brucella abortus , Brucellosis, Bovine/diagnosis , Animals , Antibodies, Bacterial/immunology , Biomarkers/blood , Brucella abortus/genetics , Brucella abortus/immunology , Brucella abortus/metabolism , Brucellosis, Bovine/immunology , Cattle , Enzyme-Linked Immunosorbent Assay/veterinary , Female , Mice , Mice, Inbred BALB C , Mutation , Recombinant Proteins/immunology , Sensitivity and SpecificityABSTRACT
A total of 27 natural products were isolated from Saussurea cauloptera, including two new eudesmane-type sesquiterpenoids, the gerin derivatives 2 and 3, and one new ent-labdane diterpenoid, compound 9. The known compounds included six sesquiterpenoids, eleven triterpenoids, six sterols, and one lignan. Their structures were elucidated on the basis of extensive spectroscopic and mass-spectrometric analyses, as well as by X-ray crystallography in the case of gerin (1). The structurally related compounds 1-4 were found to exhibit strong inhibitory activities against human gastric carcinoma (SGC-7901) cells.
