Described herein is a Mycobacterium mutant, comprising at least one mutation in at least one gene sequence encoding global gene regulators (GGRs) selected from the group consisting of sigH, sigL, sigE, ECF-1, and mixtures thereof, wherein the GGR gene is at least partially inactivated. Described herein also is a vaccine based on the mutant and a method of differentiating between subjects that have been infected with Mycobacterium and subjects that have not been infected with Mycobacterium or have been vaccinated with a Mycobacterium vaccine.