Enumeration and quantification of <i>M. leprae</i> in mouse FPs by molecular assays.

<p>BALB/c (gray bars) and athymic <i>nu/nu</i> (black bars) mice were infected in with 3×10⁷<i>M. leprae</i>. FP tissues were fixed in 70% ethanol on day 1 and at 4, 8, 12, and 17 weeks post infection. DNA and RNA were purified using a FastPrep protocol. <i>M. leprae</i> were enumerated by RLEP PCR on the DNA fraction (A). cDNA was prepared from an RNA equivalent of 3×10³<i>M. leprae</i> for determination of viability by <i>hsp18</i> (B) and <i>esxA</i> (C) qRT-PCR. Bars represent mean and standard deviation for each group. The value at each time point was compared to its respective value at 1 day. * = probability of statistical significance (p)<0.05, ** = probability of statistical significance (p)<0.01, and *** = probability of statistical significance (p)<0.001.