Ultrastructural analysis of cell wall of drug resistant and sensitive Mycobacterium tuberculosis isolated from cerebrospinal fluid by transmission electron microscope

: Drug-resistant tuberculosis is being increasingly recognized and is one among the leading cause of death worldwide. Remarkable impermeability of cell wall to antituberculous drugs protects the mycobacteria from drug action. The present study analyzed the cell wall thickness among first-line drug resistant and sensitive Mycobacterium tuberculosis (Mtb) isolated from cerebrospinal fluid by transmission electron microscopy (TEM). The average thickness of the cell wall of sensitive isolates was 13.60 ± 0.98 nm. The maximum difference (26.48%) in the cell wall thickness was seen among multi-drug resistant (18.50 ± 1.71 nm) isolates and the least difference (4.14%) was shown by streptomycin-resistant (14.18 ± 1.38 nm) isolates. The ultrastructural study showed evident differences in the cell wall thickness among sensitive and resistant isolates. Preliminary TEM examination of cells indicates that morphological changes occur in the cell wall which might be attributed to the drug resistance. The thickened wall of Mtb appears to help the bacilli to overcome the action of antituberculous drugs.