Presence of F. tularensis subsp. novicida in the GI tract at early time points. As a way to discard the possibility of swallowing of the inoculum during i.n and i.t infections we tested an endotracheal entubation of mice to directly deliver 35S labeled F. tularensis subsp. novicida into the trachea. Data shown represent an average of 3–4 mice and is given as cpm/g. Our biodistribution results showed that after 2 hrs p.i the majority of the labeled organisms were present in the lung and trachea; furthermore, a high proportion of labeled organisms were present in the stomach. In addition, after 20 hrs p.i the highest amount of labeled bacteria was present in the lung and further disseminated to other tissues including the cecum.