Analysis On The Genotyping Of Mycobacteirum Tuberculosis Clinical Isolates For462Pulmonary Tuberculosis Patients By MLVA

Objective By using typing methods of MLVA, the thesis explores the genotypes,trend and distribution of Mycobacterium tuberculosis in tuberculosis hospital of JilinProvince, and provides theoretical basis for prevention and control to the tuberculosisof Jilin Province.Methods At the beginning phase of the research, M. tuberculosis isolates ofpatients’ sputum samples were collected from2011to2012in tuberculosis hospital ofJilin Province, following a preliminary study on its genotypes using MLVA. In theresearch, the genotyping of twelve variable number of tandem repeats （VNTR） lociwere detected. Also, the test results were analyzed by Totalab software and the Clusteranalysis results were obtained by BioNumerics6.0.Various factors in clusters of462strains of Mycobacterium tuberculosis genotypes,186dominant strains and Beijingfamily genotype obtained by comparing database were all statistically analyzed bySPSS13.0.Results （1） The detection of12VNTR loci showed that there was significantgenetic polymorphism existing in the462Mycobacterium tuberculosis of clinicalisolates. Hunter-Gaston index of12VNTR loci went from0.756to0.296, in whichthe four VNTR loci of MIRU26, MIRU31, MIRU10and MIRU40owned higherresolution, the ones of MIRU16, MIRU4, MIRU39, MIRU27, MIRU23, MIRU24,MIRU2, MIRU20owned middle resolution, and MIRU20was the lowest VNTRloci.（2） By Ward method,463strains （including462clinical isolates and one standardstrain H37Rv） were genotyped to406genotypes which were divided into4genotypegroups（I, II, III, IV）. Among them, Group I made up45%（210/463） possessing210strains and191genotypes. Besides, standard strain which was mainly prevalentbacterial type was in Group I.（3）463strains（containing462clinical isolates and onestandard strain H37Rv） were divided into6genotype groups（a, b, c, d, e, f） and460genotypes by MLVA （using the nearest neighbor method）. Group a accounted for80%（371/463） was the mainly prevalent genotype. And the standard strain was in theGroup b.（4） The results showed that the Beijing family genotypes occupied70% （324/463）, and that non-Beijing family genotypes occupied30%（139/463）, aftercomparing the462clinical isolates and one standard strain with database. Besides,non-Beijing family genotypes included Bov, CAS, H₃, H₄, T₁,T₃and LAM, etc.（5）The chi-square test showed that there was no statistically significant differencebetween clustered genotypes and non-clustered genotypes in gender （χ²=0.289,P=0.591）, age （χ²=0.90, P=0.340）, treatment history （χ²=3.135, P=0.077）,comorbidities （χ²=0.404, P=0.525）, and the clinical types （P>0.05）.（6） The chi-squaretest showed that there was no statistically significant difference between dominantgenotypes and non-dominant genotypes in gender （χ²=2.803, P=0.094）, age （χ²=0.201,P=0.654）, treatment history （χ²=0.001, P=1.000） and the clinical types （χ²=0.228，P=0.633）. However, the ratio of comorbidities patients of dominant genotypes washigher than that of non-dominant genotypes （χ²=6.292, P=0.012）.（7） The chi-squaretest showed that the difference between Beijing family genotypes and non-Beijingfamily genotypes was not statistically significant in age （χ²=0.490, P=0.484）,treatment history (χ²=0.304, P=0.582, comorbidities （χ²=0.41, P=0.522） and theclinical types （P>0.05）. But, the ratio of female patients of Beijing family genotypeswas higher than that of non-Beijing family genotypes （χ²=5.909, P=0.015）.Conclusion （1） MIRU26，MIRU31，MIRU10，MIRU40are the preferred locus foranalyzing the462patients’ Mycobacterium tuberculosis genotyping in Jilin Province.（2） The462strains of Mycobacterium tuberculosis in clinical isolates showed obviousgenetic polymorphism. MLVA genotyping divided into at least four genotype groups.The predominant genotype groups were Group Ⅰ and Group a.（3） There aredifferences in main genotypes among462patients who come from different countiesand cities in Jilin Province, but most parts have the same trend with the tuberculosishospital of Jilin Province.（4） Whether462patients infect clustering genotypes hasnothing to do with gender, age, treatment history, comorbidities and the clinical types.（5） Whether462patients infect dominant genotypes has nothing to do with gender,age, treatment history, clinical types, but is only related to the comorbidities. Besides,the ratio of comorbidities patients of dominant genotypes was higher than that of non- dominant genotypes.（6） Whether462patients infect Beijing family genotypes hasnothing to do with age, treatment history, comorbidities and the clinical types, exceptgender. In addition, the ratio of female patients of Beijing family genotypes washigher than that of non-Beijing family genotypes.