Isolation of M. leprae using semi-synthetic solid agar medium

The primary isolation of M. leprae from leprous nodules was carried out using agar slant prepared by solidifying the basic compositions of M-Y series to confirm the reproducibility of the preliminary studies. Results revealed that L-Feb-75 strain represented thin membraneous growth from about 20th week and it crept up the culture tube wall at about 30th week of incubation at 37 degrees C. L-Jun-75 strain, on the other hand, exhibited numerous, white and rough colonies of submiliary size on various places of the lustreless, thin membraneous structure at the inoculation site. Thus, it was clearly demonstrated again that M. leprae could be isolated very well on the surface of agar slant of M-Y series. It is very interesting bacteriologically to note that L-Feb-75 strain formed wrinkled thin pellicle floating on the surface of liquid medium. Further, the fact that L-Jun-75 strain was isolated from a leprous nodule preserved for more than 3 months at -20 degrees C was very suggestive indicating a standard for the preservation conditions of pathological materials for at least 3 months from removal to cultivation without destroying the viability of M. leprae contained.