Figure 4. Effects of antibiotic treatments at the acute phase of leptospirosis.

C57BL/6J mice were infected with 10⁷ MFlum1 (n = 4) and injected IP daily for 5 consecutive days with penicillin G (Pen) or ciprofloxacin (Cipr) from 1 until 5 dpi (D1 to D5) or from 3 until 7 dpi (D3 to D7). Thereafter, mice were sacrificed at 25 dpi. Comparison of the dissemination kinetics for 10⁷ MFlum1 injected in albino C57BL/6J mice, treated or not with penicillin G (A) or ciprofloxacin (D). Data are expressed as the mean ± SEM of average radiance of light measured in photons/second/cm² in n = 4 for each group. p values (+p<0.05, ++p<0.01, +++p<0.001) are indicated in corresponding colors for each group versus the uninfected group. Panels (B) and (E) are corresponding bioluminescence images of half kidneys from mice sacrificed 25 dpi, from experiments depicted in panels (A) and (D), respectively. The arrows indicate the duration of the different treatments. Data are expressed as the mean ± SEM of average radiance of light measured in photons/second/cm² gated on two half kidneys in n = 4 infected mice. p values (+p<0.05, ++p<0.01, +++ p<0.001) are indicated in corresponding colors for each group versus the uninfected group. Above are shown corresponding images of the ex vivo tracking of corresponding half-kidneys after sacrifice and addition of D-luciferin. Images depict photographs overlaid with color representations of luminescence intensity, measured in photons/second/cm² and indicated on the scales, where red is most intense and purple is least intense. Panels (C) and (F) correspond to leptospiral load in urine at 25 dpi, measured by q-PCR, from experiments depicted in panel (A) and (D), respectively. Data are expressed as the mean number of leptospires in 100 µl of urine ± SEM for n = 4 infected or uninfected mice. p values (*p<0.05, **p<0.01, ***p<0.001) are indicated in corresponding colors for each group versus the uninfected group.