Screening and comparison of differentially expressed genes between one MDR-TB strain and the virulent M. tuberculosis H37Rv.

To screen and compare the differentially expressed genes between one MDR-TB strain separated from one child patient and the virulent Mycobacterium tuberculosis H37Rv, suppression subtractive hybridization (SSH) technology was used to build a library of cDNAs that were differentially expressed in the MDR and H37Rv. From this cDNA library, genes that were expressed in the MDR-TB but not in the H37Rv were selected for gene sequencing and homology analysis; 113 positive clones were obtained, their cDNA fragments were sequenced, and homology analysis was performed. Four novel sequences were identified. The results provide a partial list of genes differentially expressed in MDR-TB and four novel genes were found. Identification of these genes may contribute to our understanding of MDR-TB development.