Figure 5. ΔargT Salmonella is attenuated for virulence and shows reduced bacterial proliferation in vivo.

(A) Intracellular survival assay. BMDMs were infected at 10 MOI with the WT, ΔargT or the argT complemented strain (c- argT). Infected macrophages were lysed at 2 and 16 h post infection and the bacterial loads were determined in triplicate. 1×10⁶ bacteria each of the WT or ΔargT or the argT complement strain (c-argT) strains were inoculated orally to a group of 6 male BALB/c mice. After 5^th day of infection, homogenized samples of (B) spleen, (C) liver of the infected mice were plated on antibiotic plates and the colonies were counted. Result presented is one of three independent experiments. Statistical significance was defined as follows: *, P<0.05, **, P<0.01 (Mann-Whitney U test).