We have estimated the viability of M. leprae according to the duration and temperature
of preservation. In the distilled water or the thioglycollate medium (pH 5.6) by
morphologic index, Buddemeyer’s radiorespirometric method and PCR analysis of DNA
and RNA.
The results were as follows ;
1. Viability of M. leprae preserved at Distilled Water
1) Morphologic Index of M. leprae preserved at liquid nitrogen(-196℃, -70℃ for 1 to 7
days, was maintained more than 98%, which at 4℃ for 1 day is suitable for in vitro
study, and at room temperature(25℃) for 1 to 7 days were not suitable(p<0.01).
2) Specifically 18 kDa protein that encoding 360 bp of DNA band with M. leprae are
identified at LN2(-196℃), -70℃, 4℃ but it was unstable and decreased at
room temperature(25℃).
2. Analysis of viability of M. leprae cultured in the thioglycollate medium(pH 5.6)
1) Buddemeyer’s radiorespirometric assay
At 33℃, oxidation of [14C)-palmitic acid with M. leprae was exposed to
[14C]-labelled palmitic acid are significantly different from 25℃, 37℃.
2) DNA PCR
The 18 kDa DNA band of M. leprae are measured by DNA-polymerase chain reaction
are observed at 25℃, 33℃, 37℃ respectively without significant difference.
3) RT PCR
At 37℃, 18 kDa gene expression was increased for 1 to 3 days but decreased for 5 to
7 days and at 33℃, increased for 1 to 3 days and maintained up to 7 days. Band of 18
kDa gene was decreased after 1 day at 25℃.
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