Each species of the Brucella genus displays an affinity for specific animals or groups of animals, and Brucella abortus mostly attacks cattle and other livestock, including goats, camels, and yaks. Brucella abortus, along with Brucella melitensis and Brucella suis, are among the most virulent species and are responsible for the majority of human disease [Smith90]. Once entered in the host body, Brucella abortus multiplies in intracellular milieu of phagocytic cells such as macrophages and dendritic cells, and when a female conceives, the bacteria reach the placenta via a hematogenous route and multiply very expansively, inducing abortion [Khurana21]. Erythritol, which is abundant in genital organs of ruminants and swine, is the preferential carbon source for most brucellae, and may account at least in part for the characteristic genital tropism of brucellae [Anderson65, Barbier17].

Because of the facultative, intracellular nature of these pathogens, particularly within the phagocytic cells of the immune system, they can evade the protective activity of phagocytes and replicate within them, and they can get transported to the lymph nodes where they can be released and spread further [Smith90]. Vaccination against the organism is currently based on infection with less virulent strains, such as the RB51 strain, which does not produce the O antigen of the lipopolysaccharide (LPS), making it more susceptible to recognition by the immune system [Moriyon04, Dorneles15].

This Pathway/Genome Database (PGDB) describes Brucella abortus 2308, a virulent biovar 1 strain. Like many of the other species within the Brucella genus, it contains two chromosomes. The second chromosome contains a lower density of essential genes compared to the other chromosome and is thought to be a stabilized megaplasmid [Sternon18]. This PGDB was generated by the PathoLogic [Karp11, Karp16] component of Pathway Tools software version 24.5 and MetaCyc [Caspi18] version 24.5 on 05-Feb-2021, and has undergone substantial manual curation.

Development of this PGDB was supported by BioCyc subscription revenues and by grant GM080746 from the National Institute of Health.