Effect And Mechanism Of MTB Resistant With The MTB PhoPR TCS Deletion Mutants

Objecve:By comparing the strains epidemic in Xinjiang region of Mycobacterium tuberculosis drug-senditive strain(not drug-resistant strain), pure-resistant Mycobacterium tuberculosis clinical isolates(rifampicin,isoniazid, streptomycin, ethambutol), multidrug-resistant Mycobacterium tuberculosis clinical isolates of tuberculosis which Mycobacterium tuberculosis Pho PR two-component system(Pho P gene, Pho R gene, Pho P/Pho R gene) is missing, analyzing the reasons for the differences and investigating the regulation of its resistance to antibiotics.Methods:Using SOE-PCR technique and T vector clone technology to constructe and identify M. tuberculosis deletion mutant vectors T-Pho P 、 T-Pho R and T-Pho PR. Using the electroporation technique to transform each gene deletion mutant vectors into each group of Mycobacterium tuberculosis clinical isolates, and identify the deletion strains. Determination of minimal inhibitory concentration(MIC) by using Resazurin chromogenic method to detect the resistance changes of deletion mutants of Pho P,Pho R and Pho P/Pho R gene in Mycobacterium tuberculosis strains widely prevalent in the Xinjiang region and explore the regulation.Results:1. We have constructed Mycobacterium tuberculosis Pho PR two-component system deletion mutant vectors T-Pho P、T-Pho R and T-Pho PR.2. Constructed Pho P gene deletion mutants: Drug-sensitive-MTB△Pho P 、 INH-MTB△Pho P 、RFP-MTB△Pho P、SM-MTB△Pho P、EB-MTB△Pho P and MDR-MTB△Pho P; Pho R gene deletion mutants: Drug-sensitive-MTB△Pho R、INH-MTB△Pho R、RFP-MTB△Pho R、SM-MTB△Pho R、EB-MTB△Pho R and MDR-MTB△Pho R; Pho P/Pho R gene deletion mutants:Drug-sensitive-MTB△Pho PR 、 INH-MTB△Pho PR 、 RFP-MTB△Pho PR 、 SM-MTB△Pho PR 、EB-MTB△Pho PR and MDR-MTB△Pho PR..3. The MIC of deletion mutant of Pho P, Pho R and Pho P/Pho R gene in Mycobacterium tuberculosis strains widely prevalent in the Xinjiang region are all declining significantly, with Pho P gene deletion strains and Pho P/Pho R gene deletion strains obviously, compared with the original drug-resistant strains.Conclusions:1. In this study, Mycobacterium tuberculosis Pho PR two-component system of Pho P gene deletion mutant vector, Pho R gene deletion mutant vector and Pho P/Pho R gene deletion mutant vector were constructed successfully.2. We have constructed each group of Mycobacterium tuberculosis clinical isolates of Pho PR two-component system which Pho P gene deletion mutant strain, Pho R gene deletion mutant strains and Pho P / Pho R gene deletion mutant strain, successfully.3. Deletion mutations of Pho P gene, Pho R gene and Pho P/Pho R gene of Mycobacterium tuberculosis Pho PR two-component system are able to reduce the resistance in each group of Mycobacterium tuberculosis clinical isolates. Mycobacterium tuberculosis Pho PR two-component system can effectively regulate the resistant of Mycobacterium tuberculosis which are widespread in Xinjiang region.