Differentiation of species within mycobacterium tuberculosis complex by real-time PCR-based genomic deletion analysis

Differentiation of members within Mycobacterium tuberculosis complex (MTC) is essential for patient management and infection control. MTC is comprised of M. tuberculosis (Mtb), M. bovis (Mb), M. bovis BCG (vaccine strain; Mbcg), M. africanum (Ma), and M. microti (Mm). Because MTC have highly similar nucleotide sequences, a rapid, reliable method to distinguish species within MTC is not widely available. Genomic deletion analysis has been used, but is labor-intensive. We developed a genomic deletion assay based on real-time PCR with melting temperature (Tm) analysis to differentiate species within MTC. Conclusions: Melting analysis of RD 1, 9, and 10 can identify Mtb, Mbcg, and Ma. Development of multiplex real-time PCR with Tm analysis and additional primers to differentiate other species within MTC warrants further study and is ongoing.