MLVA For Genotyping Of Mycobacterium Tuberculosis In Xinjiang

Objective: To genotype and cluster analysis of Mycobacterium tuberculosis str ains in Xinjiang using the multi-locus variable number of tandem repeats,to under stand the genotype distribution and clustering characteristics of Mycobacterium tube rculosis in Xinjiang.Method: Using multi-stage stratified cluster equal-proportion r andom sampling method,the symptoms of the surveyed residents over the age of15 were surveyed and the chest radiographs,all the abnormal chest radiographs an d suspicious symptoms of tuberculosis were collected.Specimens were tested for s putum smear three times and sputum culture for two times.The positive sputum sa mples were identified for strain of tuberculosis infection,genomic DNA was extract ed,and then analyzed by The Multiple Locus VNTR Analysis,MLVA)classic 24-locus method for genotyping detection and analysis,and finally using Bio Numerics5.0 database for gene cluster analysis.Result: A total of 22 investigation points w ere collected and 1571 suspected TB cases were found.Among them,475 were act ive tuberculosis,50 were smear positive,103 were positive for culture,4 were non-tuberculous mycobacteria,and 99 were included in the study The results showed t hat 99 strains of Mycobacterium tuberculosis were divided into two groups(I grou p and Ⅱ group),accounting for 66.7%(66/99)in group I and 33.3% in group Ⅱ(33/99).Only two isolates from genome I were clustered at a rate of 1.5%.97 out of 99 isolates showed the "unique" genotype.Conclusion:It is preliminarily confi rmed that there are obvious genetic polymorphisms in the strains of Mycobacterium tuberculosis in Xinjiang,mainly Beijing genotype strains,and a certain proportion of non-Beijing genotypes exist at the same time.Therefore,the surveillance and management of the prevalence of major epidemic strains should be strengthened.