Mycobacterial catalases, peroxidases, and superoxide dismutases and their effects on virulence and isoniazid-susceptibility in mycobacteria – a review

Abstract

Mycobacteria are intracellular bacterial parasites which survive and proliferate inside of macrophages for long periods of time. Because mycobacterial survival in macrophages is required for virulence, a great deal of effort has been focused on identifying the genetic and physiologic determinants of intracellular survival and growth. A number of factors, among them catalases, peroxidases, and superoxide dismutase have been suggested as agents permitting mycobacteria to overcome the intracellular defences of macrophages. The characteristic features of mycobacterial catalase/peroxidases and superoxide dismutase, their distribution within the genus Mycobacterium, and their mutual interactions in the inactivation of toxic oxygen products are reviewed. Focus is placed on evidence of the role of mycobacterial catalase-peroxidase and superoxide dismutase in virulence and on the role of catalase-peroxidase in susceptibility to isonicotinic acid hydrazide.