Fig. 2.

Demonstration of lethal and sub-lethal damage of (a) E. coli and (b) S. aureus exposed to 405 nm light by comparison of post-exposure survivors plated on non-selective and selective media. Bacterial populations were exposed to an irradiance of 65 mW cm⁻². VRBA and MSA were selected for use due to their high bile and salt concentrations, respectively, to provide selective pressures which discourage growth of bacteria with reduced membrane integrity. NA was used as the non-selective growth medium. An asterisk (*) represents significant bacterial inactivation on selective agar, when compared to associated non-selective counts (P≤0.05). Each data point is a mean value±sem (n≥6).