RESUMEN
To assess the efficacy of acetohydroxyacid synthase [AHAS] inhibitors against Mycobacterium tuberculosis from China, including multidrug-resistant tuberculosis [MDR-TB] and extensively drug-resistant tuberculosis [XDR-TB] strains. In this study, the tube dilution method and Middlebrook 7H10 agar media were used to describe the in vitro efficacy of 3 AHAS inhibitors [sulfometuron methyl, monosulfuron, and monosulfuron-ester] against H37Rv and 26 clinical isolates, which include MDR-TB and XDR-TB strains, from the 309th Hospital of Chinese People's Liberation Army [PLA 309], Beijing, China. Cytotoxity of these compounds were then evaluated using the 3-[4, 5-dimethylthiazol-2yl]-2,5-dipheny tetrazolium bromide assay with HBE cells. All the experiments were performed from January 2010 to November 2010 in the Department of Clinical Laboratory of the PLA 309 hospital. Sulfometuron methyl [minimum inhibitory concentration [MIC] range, 8-16 mg/L], monosulfuron-ester [MIC range, 8-16 mg/L], and monosulfuron [MIC range, 16-64 mg/L] showed significant activity against all Mycobacterium tuberculosis strains tested in this study in vitro, and they exhibited the same degree of activity against MDR and XDR isolates with that shown against the susceptible strains. All 3 compounds showed little cytotoxicity, with an IC50 against HBE cells greater than 300 mg/L. The results suggest that AHAS could serve as a target protein for the development of novel anti-TB therapeutics in China
RESUMEN
Objective To analyze the dielectrophoresis patterns of the proteome of the Rifampin-dependent and-resistant stains of Mycobacterium tuberculosis,to search and identify the differently expressed proteins,and to provide the proteomic basis for researching the mechanism of anti-tuberculosis drug dependence of M.tuberculosis.Methods The whole somatic proteins were extracted from two strains of M.tuberculosis.The first dimensional ampholine electrophoresis was performed on immobilized pH gradient(IPG) rod gels(pH 4-7).Then the proteins on IPG strips were separated using SDS-PAGE.The stained gels were scanned with image scanner and the images were analyzed by Imagemaster 2D software.The differentially expressed proteins were detected by matrix-assisted laser desorption/ionization time of flight mass spectrometry(MALDI-TOF-MS).Results Seven hundred and fifty-three spots were detected in Rifampin-dependent strain of M.tuberculosis,while 584 spots were detected in Rifampin-resistant strain,including 404 match spots(the match rate: 61.5%).As to the expression in Rifampin-dependent strain,7 spots significantly up-regulated and 35 spots down-regulated,6 spots were absent in expression,and 5 spots expressed separately,most of the spots were small molecular proteins.Ten spots were selected to run MS analysis.Nine spots were identified as representing 7 proteins.Conclusion The Rifampin-dependent strain of M.tuberculosis is characterized by a rapid and vigorous growth mainly by means of the differential expression of enzymes related to energy metabolism and fatty acid biosynthesis.