Fig 7.

Intramacrophage survival of S. Typhi in MDMs previously stimulated with 1,25D3 (A) versus MDMs without 1,25D3 stimulation prior to infection (B). Day 11 MDMs were treated with 100 nM 1,25D3 for 24 h to induce camp gene expression or with medium alone. On day 12 (24 h after incubation with and without 1,25D3), MDMs were infected with WT S. Typhi and S. Typhi LPS modification mutants at an MOI of 1:10 for 2.5, 10, or 24 h prior to bacterial enumeration. MDMs were isolated from 2 different donors and were infected with S. Typhi in duplicate. All experiments showed similar results. The graphs represent the results from one donor. Student's t test compared intracellular survival levels between the LPS modification mutant and the WT strain enumerated at that time point. *, P < 0.05.