Fast detection of susceptibility to ethambutol drug is possible by polymerase chain reaction-restriction fragment length polymorphism. The embB306 locus is a candidate marker for rapid prediction of high resistance to anti-tuberculosis drugs for multidrug and extensively drug resistant forms of tuberculosis.

The present work is the first study on the sequence of whiB7 gene in susceptible, MDR and XDR clinical isolates. No mutation was found in this gene in strains isolated from tuberculosis patients and it was shown that the promoter and structural gene of whiB7 are highly conservative in XDR and MDR isolates. This finding confirmed the need for further studies on designing a proper inhibitor for conservative WhiB7 protein in clinical forms of M tuberculosis.