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...

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...

BACKGROUND Brucellosis is an infectious disease that is caused by Brucella spp. As Brucella spp. are intramacrophage pathogens, the treatment of this infection is very difficult. On the other hand, due to the side effects of the brucellosis treatment regime, it is necessary to find new antimicrobial agents against it. OBJECTIVES The aim of this study was to investigate the antimicrobial effec...

Brucella spp. are gram-negative intracellular pathogens that survive and multiply within phagocytic cells of their hosts. Smooth organisms present O polysaccharides (OPS) on their surface. These OPS help the bacteria avoid the bactericidal action of serum. The wboA gene, coding for the enzyme glycosyltransferase, is essential for the synthesis of O chain in Brucella. In this study, the sensitiv...

Brucella abortus is a facultative intracellular bacterial pathogen that causes abortion in domestic animals and undulant fever in humans. The mechanism of virulence of Brucella spp. is not yet fully understood. Therefore, it is crucial to identify new molecules that can function as virulence factors to better understand the host-pathogen interplay. Herein, we identified the gene encoding the ph...

SYNOPSIS A case of brucellosis due to Brucella abortus, biotype 5, occurred in a bulk milk-tanker driver who collected milk from refrigerated tanks on 23 farms. The organism was isolated from blood cultures by using a serum dextrose broth containing antibiotics. Serological investigations indicate that both abortus and melitensis antigen suspensions should be used in the investigation of cases ...

The aim of this study was to evaluate the growth of the B. abortus reference strains and field isolates on media containing different inhibitor agents. Reference strains were seeded on tryptose agar containing: i-erythritol (1.0 mg/mL), fuchsin (20 μg/mL and 80 μg/mL), thionin (2.5 μg/mL and 10 μg/mL), rifampicin (200 μg/mL) and safranin O (200 μg/mL). Field isolates were tested only on media c...

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...

background: brucellosis is one of the most common zoonosis in middle east and iran. objectives: the purpose of this study was genomic detection of brucella spp. in sero-positive dairy cattle. methods: we have collected 28,519 blood samples from cows during 2012-2013. samples were screened by slide and tube agglutination and 2-mercaptoethanol tests. samples with anti-brucella antibodies titer ≥ ...