Detection Of Drug-resistance Genes And Biological Changes Effected By Chinese Medicine Herb In Mycobacterium Tuberculosis

Mycobacterium tuberculosis (MTB) is the pathogenic bacterium of tuberculosis (TB). One-third of the global population is sure to be infected with bacteria of the Mycobacterium tuberculosis complex. More than 8 million new cases of tuberculosis occur annually leading to 2 million deaths. Nowadays, because of occurrence of drug resistance tuberculosis, especially multiple-drug resistance tuberculosis (MDR-TB) and outbreak in association with human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS), tuberculosis have became more dangerous. Therapeutic efficacy of the anti-tuberculosis drugs commonly used in clinical, such as INH RFP SM PZA and EMB, is on descent. There have been ample warnings that MDR-TB will continue to emerge if countries do not strengthen their control of TB. The aim of this study was to detect drug-resistance genes and screen herbs that could inhibit drug resistance of MTB or enhance the anti-tuberculosis drugs' effect in order to prevent and cure MTB.In this study, we obtained 38 MTB isolations from clinical by BACTEC-TB 460 system. Using of 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and microtiter plate, we assayed the minimal inhibitory concentration (MIC) of rifampin and streptomycin to the isolations. There are 17 rifampin-resistance isolations and 9 streptomycin-resistance isolations. According to the drug-resistance gene sequences of rpoB and rpsL, we designed 2 pairs of primers for PCR. By PCR and DNA sequencing, we analyzed the rifampin- and streptomycin-resistance isolations. The results were including 2 mutations identified in the rpsL gene and 3 mutations in the rpoB gene.we made some crude preparation of Chinese medicine herb selected on the basis of nature of a drug, we detected crude preparation susceptibility to the rifampin- and streptomycin-resistance isolations by MTT and microtiter plate, resulting in most of non-sensitivity. Analyzing the changes of MIC of those resistance strains after cultivation and transferring of culture, we found 2 herbs could decrease the streptomycin-resistance of isolations and 5 herbs could enhance the drug's effect. But none could take effect on rifampin-resistance isolations. Based on mechanisms of drug resistance of MTB, we analyzed the changes of the morphology, protein electrophoresis map and drug-resistance genes occurred in those isolations. The results showed that no changes occurred in the two formers and the later changed for 4 sites by contrasted with the primordial drug-resistant isolatons.