is associated with various gastrointestinal disorders. Lethal photosensitisation was investigated as a possible technique for killing which might offer a better alternative to antibiotics. The susceptibility of to lethal photosensitisation was determined by mixing suspensions of with various photosensitisers and plating out on blood agar before irradiation with low-power laser light. Five sensitisers were studied further by mixing them with in a tissue-culture plate and counting survivors after irradiation as a function of laser exposure time, dye concentration and pre-irradiation time. Crystal violet and thionin were ineffective as sensitisers, but zones of inhibition appeared with methylene blue (MB), protoporphyrin IX (PPIX), haematoporphyrin derivative (HPD), toluidine blue O (TBO) and disulphonated aluminium phthalocyanine (S2). Laser light or sensitiser alone did not affect bacterial viability. S2 (100 μg/ml) with a laser light energy density of 16 J/cm, HPD (100 μ/ml) with 160 J/cm, MB (100 μg/ml) with 21 J/cm, PPIX (150 μg/ml) with 320 J/cm and TBO (50 μg/ml) with 160 J/cm all reduced bacterial viability by > 99%. The killing of sensitised by laser light offers a new approach to the treatment of localised infections when all colonised areas are accessible to light.


Article metrics loading...

Loading full text...

Full text loading...


Most cited this month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error