A Novel marRAB Operon Contributes to the Rifampicin Resistance in Mycobacterium smegmatis
Figure 9
Determination of RIF transport and absorption by M. smegmatis.
HPLC assays were performed as described in “Experimental Procedures”. The relationship of standard curve between RIF concentration and peak area was acquired through a series of concentration gradient standard RIF. A standard curve equation Y = 28403X−6721 (r = 0.9988) was obtained, in which Y represents peak area (µV×s), X represents RIF concentration (µg/ml) and r is the correlation coefficient. The samples peak area, from Msm/pMV261, Msm/pMV261-Ms6509–6510 and Msm Ms6509–6510: hyg/pMV261, was put into the standard curve equation and the RIF concentration of samples could be calculated. Each sample peak area was determined independently for three times. The quantity of the absorbed RIF by M. smegmatis was obtained by calculating the change of RIF concentration between two time points. Relative expression data were analyzed for statistical significance by the unpaired two-tailed Student’s T-test using GraphPad Prism (Version 5).
