A novel method of Mycobacterium tuberculosis complex strain differentiation using polymorphic GC-rich gene sequences

Tuberculosis is one of the leading infectious diseases. In this work, a new genotyping method of Mycobacterium tuberculosis (Mtb) complex strain is presented. 27 Mtb genomes were analyzed for the presence of length polymorphism within polymorphic GC-rich gene sequences. Four genes, Rv3345c, Rv3507, Rv0747 and Rv3511, showing variation in length depending on the Mtb strain were selected for designing primer sequences flanking variable regions for the PCR method. Identification of 16 genotypes among 27 analyzed genomes demonstrated usefulness of our genotyping method in differentiation of Mtb genomes based on sequence polymorphism in the four PGRS genes.