Scatter plot and mean ± SD of CFU recovery for mice infected with 108S. pneumoniae cells and treated with only PBS instillation (Control), PBS instillation followed by 120 J/cm2 of light dose (Light), only 100 μmol/L of indocyanine green instillation (ICG), or a combination of 100 μmol/L of indocyanine green instillation and 120 J/cm2 of light dose (PDT). * P ˂ 0.05 versus Control, test Mann‐Whitney, n = 4–5 each. CFU, colony‐forming units; ICG, indocyanine green; PBS, phosphate‐buffered saline.
Kaplan‐Meier curve shows the survival of untreated control mice and mice treated with PDT (120 J/cm2 of light + 100 μmol/L of ICG) over 50 days post‐infection with 108S. pneumoniae cells. Treatment was performed 2 days after the bacterial inoculation. In the control group, 60% of animals (3 out of 5) died within 32 days following infection. However, no animals died in the Photodynamic Therapy group over the 50 days following infection.
(A) Custom‐made illumination device contending 18 laser diodes generating illumination of the animal's thorax at 780 nm. The arrows illustrate the laser beam propagation. (B) Animal positioning during the irradiation procedure.