Project description:Extensively drug resistant tuberculosis (XDR-TB) showed many different characteristics including the extreme drug resistance versus the drug sensitive clinical isolates (DS-TB), to know better about the reasons we used the tuberculosis host cells named as THP-1 (one kind of the macrophage cells) to be infected by the XDR-TB and DS-TB.DS strain A36 and the XDR strain B42 and was typical and selected by our lab. Then the total RNA of infected or uninfected THP-1 cells was extract and purified for the analysis by the chip (22K Human Genome chip representing the 21522 ORF of human with the oligonucleotide probe of 70 mer from CapitalBio Corp., Beijing, China). The results reflected the different expressed genes involved in apoptosis, secreted cytokines and signal pathway and so on. Those results might indicate the how the XDR-TB cause the pathogenesis.
Project description:Rifampicin plays an important role during tuberculosis treatment, which historically contributed for shortening therapy; however, rifampicin resistance has been the intersection for the definition of multi (MDR-TB) and extensively (XDR-TB) resistant outcomes. A key aspect which has contributed for investigations of drug action/resistance is the understanding of the dynamic genome expression, as that analyzed by Proteomics. Proteins from the reference strain, Mycobacterium tuberculosis H37Rv were extracted after 12, 24 and 48 hours over rifampicin challenge at the minimal inhibitory concentration (0.03 μg•mL-1) and identified by LC-MS.
Project description:The emergence of drug resistance among tuberculosis (TB) patients is often associated with their non-compliance to the length of the chemotherapy, which can reach up to 2 years for the treatment of multi-drug-resistant (MDR) TB. Drugs that would kill TB faster and would not lead to the development of drug resistance could shorten chemotherapy significantly. In Escherichia coli, the common mechanism of cell death by bactericidal antibiotics is the generation of highly reactive hydroxyl radicals via the Fenton reaction. Since ascorbic acid (vitamin C) is known to drive the Fenton reaction, we tested whether the Fenton reaction could lead to a bactericidal event in Mycobacterium tuberculosis by treating M. tuberculosis cultures with vitamin C. Here, we report that the addition of vitamin C to drug-susceptible, MDR and extensively drug-resistant (XDR) M. tuberculosis strains results in sterilization of the cultures in vitro. We show that the sterilizing effect of vitamin C on M. tuberculosis was dependent on the production of high ferrous ion levels and reactive oxygen species. Although, this potent sterilizing activity of vitamin C against M. tuberculosis in vitro was not observed in mice, we believe this activity needs further investigation.
