No abstract

Aim: To determine the influence of several factors on the inactivation of micro-organisms by intense light pulses (ILP). Methods and Results: Micro-organisms on agar media were flashed 50 times under different conditions and their inactivation measured. Micro-organisms differed in sensitivity to ILP but no pattern was observed among different groups. Several enumeration methods to quantify the effect of ILP were investigated and showed relevant differences, shading effect and photoreactivation accounted for them, the strike method yielded the most reliable results. Higher decontamination efficiencies were obtained for Petri dishes located close to the strobe and inside the illumination cone. Decontamination efficacy decreased significantly at contamination levels >6AE85 log 10 . After 13 successive treatments, no resistance to ILP could be demonstrated. Media warming up depended on the distance from the strobe and the number of flashes.

No abstract