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Objective: a preliminary understanding of Chongqing Children Mycobacterium tuberculosis clinical isolates variable number tandem repeats (Variable number tandem repeats, VNTR) the distribution characteristics of the region and to find suitable combinations of VNTR loci. 2, to understand children Mycobacterium tuberculosis in vivo gene mutation and clinical manifestations PE_PGRS33 between. 3, to understand the existence of childhood tuberculosis in children in vivo mixed infections, and Mycobacterium tuberculosis PE_PGRS33 genetic subtypes exist group characteristics. Method: 1, using multilocus tandem repeats (Multiple locus VNTR analysis, MLVA) typing method, the selection criteria 24 VNTR loci, for 101 cases of clinical isolates of Mycobacterium tuberculosis DNA testing, the results using BioNumerics 6.1 database software for cluster analysis and resolution locus Hunter-Gaston index (Hunter-Gaston index, HGI) analysis, and comparative analysis of international recommended grouping (12 points, 15 points, 24 points) genotyping identification capability. 2,101 cases of Mycobacterium tuberculosis clinical isolates PE_PGRS33 genes through sequence alignment, gene mutation and analyzed the relationship between the clinical phenotype. 3, select the five cases diagnosed as miliary tuberculosis combined initial treatment of tuberculous meningitis in children, their foster the growth of Mycobacterium tuberculosis good and obvious gaps single colonies cultured colonies isolated clones were obtained 116 Mycobacterium tuberculosis clones, its MLVA genotyping and gene sequence analysis PE_PGRS33. Results: 1, MLVA analysis showed 24 VNTR loci in different strains obvious polymorphism, 101 cases of Mycobacterium tuberculosis clinical isolates can be divided into a group of 83 kinds of gene genotypes, 69 genotypes Only one strain, accounting for 68.32% (69/101), and another 32 clinical isolates showed 14 kinds of genotypes, accounting for 31.68% (32/101), clustering was 17.82%; 24 VNTR loci HGI with large difference (0.168 ~ 0.829), HGI can reach more than 0.5 VNTR loci, 16; 24 different VNTR loci locus combinations: 12, 15, and 24 loci were combined HGI as 0.995,0.996,0.996. 2,101 cases of Mycobacterium tuberculosis clinical isolates exist 12 kinds PE_PGRS33 genotypes, of which 59.41% of clinical isolates with PE_PGRS33 genetic mutation can cause PE_PGRS33 protein amino acid sequence changes in genes that exist variability of Mycobacterium tuberculosis through statistical analysis, discovery and clinical manifestations of tuberculous meningitis associated with PPD negative. 3,116 strains of Mycobacterium tuberculosis clones through MLVA genotyping, showing the five genotypes. Clone from the same children their same genotype, different parts of the same patients whose genotype has the same clone; 116 Mycobacterium tuberculosis clones PE_PGRS33 gene sequence analysis by comparison of the performance of the two types of sequences variability. One kind of insertional mutagenesis combined point mutations, deletions another one kind of joint point mutations. Children from the same clone its PE_PGRS33 genetic variation of the same type, the same children in different parts of clones whose PE_PGRS33 also the same type of genetic variation. Conclusions: 1, children in Chongqing in Mycobacterium tuberculosis gene polymorphism exists, the international recommended 15 VNTR loci combined MLVA typing methods for children in the region in Mycobacterium tuberculosis epidemiological studies. 2, PE_PGRS33 gene and there is a link between the clinical phenotype, the gene mutation easily in the clinical manifestations of tuberculous meningitis with PPD negative. 3, TB patients from a single isolated polyclonal Mycobacterium tuberculosis its genotype homogeneity, and its PE_PGRS33 gene is also the same as described previously untreated patients infected with tuberculosis is unitary, there is mixed infections.
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