Molecular characteristics of rifampin and isoniazid resistant Mycobacterium tuberculosis strains from Beijing,China  

作　　者：JIAO Wei-wei Mokrousov Igor SUN Gui-zhi LI Mo LIU Jia-wen Narvskaya Olga SHEN A-dong 

机构地区：[1]Beijing Pediatric Institute, Beijing Children＇s Hospital Affiliated to Capital Medical University, Beijing 100045, China [2]Laboratory of Molecular Microbiology, St. Petersburg Pasteur Institute, St. Petersburg 197101, Russia [3]Clinical Laboratory, Beijing Chest Hospital, Beijing 100095, China

出　　处：《Chinese Medical Journal》2007年第9期814-819,共6页中华医学杂志（英文版）

基　　金：This study was supported by a grant from the National Natural Science Foundation of China(No.30471841).

摘　　要：Background China is one of the high burden countries of Mycobacterium tuberculosis （TB） infection globally, with high incidence and mortality. We studied the molecular characteristics of rifampin （RIF） and isoniazid （INH） resistant Mycobacterium tuberculosis strains from Beijing, China, in order to find out the genetic marker for rapid detection of specific drug resistance.Methods Forty pansusceptible and 81 resistant strains of Mycobacterium tuberculosis isolated from Beijing, China during 2002-2005 were analyzed. The modified rifampin oligonucleotide （RIFO） assay based on reverse line blot hybridization was used to detect mutations in the 81 bp hot-spot region of rpoB gene, which is associated with RIF resistance. The INH resistance associated genes, regulatory region mab-inhA （-15C/T） and structural gene katG S315T were detected by reverse line blot hybridization and PCR-restriction fragment length polymorphism （RFLP） method respectively. All the strains were typed by spoligotying and the Beijing genotype was further subdivided by NTF locus analysis. The distribution of drug resistance associated mutations in the above genes was compared in these groups. Results Sixty-five （91.5%） of 71 RIF resistant and 52 （92.9%） of 56 multidrug-resistant （MDR, i.e. resistant to at least RIF and INH） strains were found to harbor mutations in the rpoB hot-spot region. No mutation was detected in RIF sensitive strains. The specificity and sensitivity of the modified RIFO assay were 100% and 91.5%, respectively, katG315 AGC〉ACC and inhA-15C〉T mutations were found in 40 （60.6%） and 10 （15.2%） of 66 INH resistant strains, respectively; 7.6% of INH-resistant strains had mutations in both of these genes. Therefore, a combined use of both katG315 and inhA-15 identified 68.2% of INH-resistant strains. The Beijing genotype accounted for 91.7% of total strains and was further subdivided into ＂modern＂ （76.6%） and ＂ancestral＂ （23.4%） group. There is no significant differenceBackground China is one of the high burden countries of Mycobacterium tuberculosis （TB） infection globally, with high incidence and mortality. We studied the molecular characteristics of rifampin （RIF） and isoniazid （INH） resistant Mycobacterium tuberculosis strains from Beijing, China, in order to find out the genetic marker for rapid detection of specific drug resistance.Methods Forty pansusceptible and 81 resistant strains of Mycobacterium tuberculosis isolated from Beijing, China during 2002-2005 were analyzed. The modified rifampin oligonucleotide （RIFO） assay based on reverse line blot hybridization was used to detect mutations in the 81 bp hot-spot region of rpoB gene, which is associated with RIF resistance. The INH resistance associated genes, regulatory region mab-inhA （-15C/T） and structural gene katG S315T were detected by reverse line blot hybridization and PCR-restriction fragment length polymorphism （RFLP） method respectively. All the strains were typed by spoligotying and the Beijing genotype was further subdivided by NTF locus analysis. The distribution of drug resistance associated mutations in the above genes was compared in these groups. Results Sixty-five （91.5%） of 71 RIF resistant and 52 （92.9%） of 56 multidrug-resistant （MDR, i.e. resistant to at least RIF and INH） strains were found to harbor mutations in the rpoB hot-spot region. No mutation was detected in RIF sensitive strains. The specificity and sensitivity of the modified RIFO assay were 100% and 91.5%, respectively, katG315 AGC〉ACC and inhA-15C〉T mutations were found in 40 （60.6%） and 10 （15.2%） of 66 INH resistant strains, respectively; 7.6% of INH-resistant strains had mutations in both of these genes. Therefore, a combined use of both katG315 and inhA-15 identified 68.2% of INH-resistant strains. The Beijing genotype accounted for 91.7% of total strains and was further subdivided into ＂modern＂ （76.6%） and ＂ancestral＂ （23.4%） group. There is no significant difference

关 键 词：Mycobacterium tuberculosis drug resistance RIFAMPIN ISONIAZID 

分 类 号：R378.911[医药卫生—病原生物学] R978.3[医药卫生—基础医学]