Discovering Novel Genes that Allow Bacillus anthracis to Survive Host Defenses
Bacillus anthracis is a bacterium that causes the deadly disease anthrax and has been used in bioterrorism. We are looking to investigate what genes within the chromosomal DNA contribute to the virulence of Bacillus anthracis. In this study, we screened a transposon library of B. anthracis ?knock-out? mutants for susceptibility to reactive oxygen species used by the immune system. A broad in vitro hydrogen peroxide screen was performed on 1,953 transposon mutants, and after several rounds of in vitro screening, 40 mutants were identified as consistently attenuated in the presence of hydrogen peroxide. Four of these mutants were then tested in the invertebrate model, Galleria mellonella, to assess virulence in an animal model. Mutants with phenotypes that repeated in both assays were prioritized for characterization. The location of the transposon insertion in one of the mutants was successfully identified. Identifying these novel genes contributing to the bacterium?s virulence will provide a better understanding of B. anthracis pathogenesis and may provide potential targets for combatting anthrax.