Fig 5. Persistence is a more balanced strategy than tolerance.

(A) Illustration of the in cellulo competition assay where BMDMs were co-infected with the WT/shpAB1 or WT/ΔhisG pair and treated with cefotaxime to assess antibiotic survival (+AB) or gentamicin to assess proliferation (-AB). WT expressed GFP constitutively whereas the shpAB1 and ΔhisG mutants expressed mCherry. (B) Left panel, representative images of the bacterial population after extraction of 24 h gentamicin (-AB) or cefotaxime (+AB) treated BMDM. For the proliferation competitive assay (-AB), ten-fold dilution series were spotted on rich medium plate. For the antibiotic survival competitive assay (+AB), the entire bacterial population was plated on rich medium. Right panel, competitive index ratios. Data represent the mean and SD of at least three biological repeats. Statistically significant differences of each pair by two-sided t-test are indicated as ***p<0.001. (C) Illustration of the in vivo mice co-infection assay with the WT/shpAB1 or WT/ΔhisG pair used on panel A and B. Two days after oral gavage, mice were either sacrificed or treated with cefotaxime for 4 or 6 days. (D-E) Bacterial survival in the spleen of the WT/ ΔhisG (D) and WT /shpAB1 (E) mix. Results are expressed in percentage of the total population recovered on plate. Day 0 indicates the inoculum ratio. Statistical significant differences at each timepoint by two-sided t-test are indicated as *p<0.05 and ***p<0.001. In vivo mice experiments were carried out with at least 4 animals per time point.