Project description:These samples are part of an experiment comparing the expression profiles of Francisella tularensis novicida grown in chemically defined medium and bacteria isolated 24 hours post infection of J774 macrophages to identify virulence factors
Project description:We used an inhalation mouse model of infection to query a collection of 2149 mutants in a Francisella tularensis subsp. novicida background for genes required for growth, survival and systemic dissemination. A microarray-based genome-wide negative selection screen (Microarray tracking of transposon mutants = MATT) allowed us to monitor the behavior of transposon insertions in 1371 unique genes. Interestingly most of these genes persisted in lung and colonized liver and spleen. We found 44 (35%) genes negatively selected in lung and 81 (65%) genes negatively selected in liver and/or spleen. If negative selection in lung occurred, the attenuated mutants in general persisted at 24h after infection, disseminated to liver and/or spleen and appeared to be lost in lung after 48 to 72h of infection. These genes with a strong phenotype in lung but also potential for dissemination might be attractive vaccine or drug candidates. Keywords: Genome-Wide Negative Selection Screen