The Fischer 344 Rat Reflects Human Susceptibility to Francisella Pulmonary Challenge and Provides a New Platform for Virulence and Protection Studies
Figure 2
Uptake and replication of Francisella strains within Fischer 344 rat BMDM.
Bone marrow derived macrophages from Fischer 344 rats were seeded in 96 well plates (2×105 cells/well) and allowed to adhere. Cells were infected (10 or 100 MOI) for two hr with subsp. novicida, LVS, subsp. holarctica, or subsp. tularensis. (A) Serial dilutions of culture supernatants (extracellular bacteria) and cell lysates (intracellular bacteria) at (i) 10 MOI and (ii) 100 MOI were plated to determine ability of macrophages to take up bacteria. Results are representative of two separate experiments. (B) Following a 2 hr infection period, cells were treated with gentamicin for 1 hr, and then incubated at 37°C for 72 hr. At the indicated time points (3, 24, 48 and 72 h), cells were lysed and serial dilutions of lysates were plated to quantify intracellular bacteria. Intracellular replication profiles of (i) subsp. novicida, (ii) LVS, (iii) subsp. holarctica, or (iv) subsp. tularensis. Results are representative of at least three separate experiments.