Laser-Raman spectroscopy: a novel approach for sensitive molecular characterization of the mycobacterium genomic DNAs

ABSTRACT

In the present work we give a detailed analysis on the key Raman markers of genomic DNA for four species of Mycobacterium namely Mycobacterium tuberculosis, Mycobacterium bovis, Mycobacterium avium and Mycobacterium phlei. The fundamental groups of bands have done for the first time to these Mycobacterium genomic DNAs. Molecular Laser Raman Spectroscopy [MLRS]; a novel and highly sensitive method, was used for whole genome characterization and comparison of the four species under investigation. The Raman spectroscopic analysis showed, in the M. avium and M. bovis the DNA is more rich in A+T as compared with the others, while the M. phlei and M tuberculosis are more rich in G+C. Moreover, a detailed analysis of all the bands diagnostic of B-form backbone geometry; the phosphate groups, bands diagnostic of deoxynucleoside conformation, ring vibrations of the bases, carbonyl stretching modes of thymine, guanine and cytosine was given here for the four mycobacterial species DNAs. The present study describes the use of [MLRS], as a novel promising assay, for rapid and discriminative detection of a mycobacterial genome with no confusion with other bacteria, utilizing genomes of four different mycobacteria species. In addition, Molecular Polymorphic Laser Raman Spectroscopy fingerprints and / or sequences may serve as markers that provide a basis for virulence, phylogenetic and evolutionary studies