realized in has disposition at some time agent_in_compromised_process unfolds_in HeLa cell artificially mutated Brucella B. abortus hemH mutant MUTATION: A hemH knockout B. abortus mutant displayed auxotrophy for hemin, defective intracellular survival inside J774 and HeLa cells, and lack of virulence in BALBc mice. This phenotype was overcome by complementing the mutant strain with a plasmid harboring wild-type hemH. These data demonstrate that B abortus synthesizes its own heme and also has the ability to use an external source of heme [Ref6472:Almirón et al., 2001]. See PMID:11553564 macrophage - Brucella interaction attenuated disposition Hela cell - Brucella interaction mouse - Brucella interaction Brucella intracellular survival