Life on the inside: Probing Mycobacterium tuberculosis gene expression during infection

The identification of Mycobacterium tuberculosis genes specifically express ed during infection is a key step in understanding mycobacterial pathogenes is. Such genes most likely encode products required for survival within the host and for progressive infection. Recent advances in mycobacterial genet ics have permitted the development of new techniques and the adaptation of existing methods to analyse mycobacterial in vivo gene expression and virul ence. This has revealed a subset of M. tuberculosis genes that are differen tially expressed during infection and has demonstrated that a number of com ponents contribute to the virulence of the organism. This information is ex pected to provide new strategies to prevent tuberculosis infection, new tar gets for antimicrobial therapy and new insights into the infectious process .