Introduction and objective: Outer membrane proteins (OMPs) of Brucella are considered as immunogenic structures which can be used to design and develop a subunit vaccine for human brucellosis. Brucella abortus S99 OMPs promote the synthesis of high levels of specific anti-Brucella IgG molecules in rabbits when administrated with lipopolysaccharide (LPS). The objective of this study is evaluatio...

Brucella abortus is a Gram-negative, facultative intracellular bacterium that causes brucellosis, a worldwide zoonotic disease leading to undulant fever in humans and abortion in cattle. The immune response against this bacterium relies on the recognition of microbial pathogen-associated molecular patterns, such as lipoproteins, lipopolysaccharides, and DNA; however, the immunostimulatory poten...

Brucella spp. are highly adapted intracellular pathogens of mammals that cause chronic infections while surving and replicating in host monocytes and macrophages. Although monocytes are normally susceptible to infection, pretreatment with pro-inflammatory cytokine interferon-γ (IFN-γ) activates cellular defense mechanisms that increase intracellular killing of Brucella and prevents bacterial re...

znuA is known to be an important factor for survival and normal growth under low Zn(2+) concentrations for Escherichia coli, Haemophilus spp., Neisseria gonorrhoeae, and Pasteurella multocida. We hypothesized that the znuA gene present in Brucella melitensis 16 M would be similar to znuA in B. abortus and questioned whether it may also be an important factor for growth and virulence of Brucella...

Cells in the Brucella spp. are intracellular pathogens that survive and replicate within host monocytes. Brucella maintains persistent infections in animals despite the production of high levels of anti-Brucella-specific antibodies. To determine the effect of antibody opsonization on the ability of Brucella to establish itself within monocytes, the intracellular trafficking of virulent Brucella...

BACKGROUND Virulence of pathogenic bacteria is often determined by their ability to adapt to stress. RESULTS The Brucella abortus general stress response (GSR) system is required for chronic mammalian infection and is regulated by phosphorylation and proteolysis. CONCLUSION The B. abortus GSR signaling pathway has multiple layers of post-translational control and is a determinant of chronic...

Brucella abortus (B. abortus) is a facultative intracellular pathogen that can survive inside macrophages and trophoblast giant cells, and the causative agent of brucellosis. In the present study, we found that production of regulated upon activation normal T-cell expressed and secreted (RANTES) due to B. abortus infection contributes to abortion in pregnant mice. B. abortus infected pregnant i...

The outer membrane (OM) of the intracellular parasite Brucella abortus is permeable to hydrophobic probes and resistant to destabilization by polycationic peptides and EDTA. The significance of these unusual properties was investigated in a comparative study with the opportunistic pathogens of the genus Ochrobactrum, the closest known Brucella relative. Ochrobactrum spp. OMs were impermeable to...

The products of the Brucella abortus virB gene locus, which are highly similar to conjugative DNA transfer system, enable the bacterium to replicate within macrophage vacuoles. The replicative phagosome is thought to be established by the interaction of a substrate of the VirB complex with macrophages, although the substrate and its host cellular target have not yet been identified. We report h...

The live attenuated Brucella abortus strain RB51 is a rifampin-resistant, lipopolysaccharide (LPS) O-chain-deficient mutant of virulent B. abortus 2308. The reduced O-chain content in RB51 prevents this bacterium from inducing antibodies detectable by the conventional serologic tests for bovine brucellosis diagnosis that mainly identify antibodies to LPS. The absence of available serologic test...