Dye mediated photoinactivation of bacteriophages by nitrogen laser

The nitrogen laser (lambda = 337.1 nm) was documented to have photosensitiz ed inactivation of bacteriophages P1 and phage A having Escherichia coil an d Salmonella typhi as their respective hosts. Methylene blue and crystal vi olet had a direct virucidal effect whereas toluidine blue revealed accentua ted lethal effect on photosensitization with N-2 laser for both of the bact eriophages taken in the study. The other dyes such as congo red, neutral re d, auramin O and safranine showed differences in their virucidal activity a mong the two bacteriophages. However, malachite green did not show any chan ge for the two viruses both by itself and on irradiation with the laser. A possibility of photosensitizing effect of N-2 laser for the therapy of vira l infections needs to be explored.