TABLE 1.

Effect of PDT on extracellular and intracellular M. bovis BCG (Pasteur)^a

Treatment of BCG cells	% Survival after treatment (mean ± SE)
BPD only	87.0 ± 12.3
Light only	104.0 ± 4.9
BPD and light	26.0 ± 14.4**
BPD and light in J774 monolayer	49.0 ± 22.0

^aSurvival of BCG cells following exposure to BPD only (5 μM BPD for 1 h), light only (60 J/cm² of 690-nm light), and both BPD and light (5 μM BPD for 1 h and 60 J/cm² of 690-nm light). Survival is expressed as a percentage of the control± standard error. Control samples (set to 100%) contained 2 × 10⁸ bacteria/ml of log-phase cells. Values represent means from four independent experiments. For survival of BCG cells in a J774 monolayer, PDT-treated samples were expressed as percentages of control BCG cells in a J774 monolayer (100%), and the value represents the mean from three independent experiments ± standard error. Viability in all experiments was determined using the radiolabeled uracil uptake assay. **, P < 0.01.