Isolation of mycobacterial phage from the laboratory strain Mycobacterium leprae murium "Douglas"

The colony microstructure of the laboratory strain Mycobacterium leprae murium "Douglas" cultivated on Ogawa's egg medium was examined. A bioptical sample from the liver of a white mouse subcutaneously infected and observed for ten months was used as inoculum. The inoculum contained 5.2 X 10(9) acidfast rods. The Ogawa's media were incubated in 5% atmosphere of CO2 at 33 degrees C to 37 degrees C for 6 to 10 months. The outgrown colonies were killed with a formol solution, then embedded into the agarparaffin and cut out with the aid of Reichert's microtom. In thin sections there was an apparent vacuolisation of colonies proving the presence of the temperate phage, which was isolated from the bacterial suspension inoculated on the host non lysogenic strain Mycobacterium smegmatis ATCC 607. On the simple agar medium N-4 the number of 2.4 X 10(9) living particles was achieved, which shows the possible use of this phage for differential diagnostic purposes in the taxonomy studies of mycobacteria.