[Study on the molecular epidemiology of Mycobacterium tuberculosis in Shanghai]

To explore the molecular-epidemiology of Mycobacterium tuberculosis in Shanghai.

Drug-resistant and drug-susceptible strains of M. tuberculosis were randomly selected from the bank of M. tuberculosis of Shanghai Municipal Center for Disease Control and Prevention and were genotyped by mycobacterial interspersed repetitive units(MIRU) and Spoligotyping methods. The genotyping results were analyzed and combined with epidemiological data.

The Spoligotyping results demonstrated that 89 % (81/91) of the strains belonged to the Beijing genotype. Of the patients who had received BCG-vaccination,88.5% (54/61) infected with strains of Beijing genotype and 90.0% (27/30) of the patients were not BCG-vaccinated. However, the difference was not statistically significant. Drug-resistant rate from those strains of Beijing genotype was 45.7 (37/81), lower than that of non-Beijing genotype (60.0% ,6/10). Again,the difference was not statistically significant. The MIRU results showed that 62.6 % (57/91) were strains of clusters.

The Beijing genotype of M. tuberculosis were found to be the dominant strains in Shanghai. The associations between Beijing genotype strains and BCG vaccination or drug-resistant were not found. Results from cluster analysis suggested that some cases might belong to the newly developed cases.