background and objectives: brucella, causative of brucellosis, has some potential virulence factors involved in brucella replication and its strategies to circumvent the immune response. one of them is the virb gene that encodes the type іv secretion system proteins (t4ss) involved in intracellular replication of organism. brucella virulence factor a ( bvf a), and urease ( ure ) has also been d...

Human health is threatened by various infectious bacterial pathogens but is also supported by many commensal bacteria particularly in the intestinal tract. However, many of the bacterial pathogens and commensal bacteria are taxonomically indistinguishable, with pathogenic and commensal bacteria existing in the same genus and even species. A typical example is Escherichia coli, which is commonly...

A wide variety of plant and human bacterial pathogens use a specialized 'type III' protein secretion system to deliver virulence factors into host cells. Appendage-like surface structures have recently been identified on several bacterial pathogens and there are indications that these may be conduits for virulence factor delivery.